scispace - formally typeset
Search or ask a question

Showing papers on "Methanol published in 2015"


Journal ArticleDOI
TL;DR: The mordenite micropores provide a perfect confined environment for the highly selective stabilization of trinuclear copper-oxo clusters that exhibit a high reactivity towards activation of carbon–hydrogen bonds in methane and its subsequent transformation to methanol.
Abstract: Copper-exchanged zeolites with mordenite structure mimic the nuclearity and reactivity of active sites in particulate methane monooxygenase, which are enzymes able to selectively oxidize methane to methanol. Here we show that the mordenite micropores provide a perfect confined environment for the highly selective stabilization of trinuclear copper-oxo clusters that exhibit a high reactivity towards activation of carbon–hydrogen bonds in methane and its subsequent transformation to methanol. The similarity with the enzymatic systems is also implied from the similarity of the reversible rearrangements of the trinuclear clusters occurring during the selective transformations of methane along the reaction path towards methanol, in both the enzyme system and copper-exchanged mordenite.

565 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a review of recent results and developments in heterogeneous catalytic methane conversion to synthesis gas, hydrogen cyanide, ethylene, methanol, formaldehyde, methyl chloride, methyl bromide and aromatics.
Abstract: Methane activation by heterogeneous catalysis will play a key role to secure the supply of energy, chemicals and fuels in the future. Methane is the main constituent of natural gas and biogas and it is also found in crystalline hydrates at the continental slopes of many oceans and in permafrost areas. In view of this vast reserves and resources, the use of methane as chemical feedstock has to be intensified. The present review presents recent results and developments in heterogeneous catalytic methane conversion to synthesis gas, hydrogen cyanide, ethylene, methanol, formaldehyde, methyl chloride, methyl bromide and aromatics. After presenting recent estimates of methane reserves and resources the physico-chemical challenges of methane activation are discussed. Subsequent to this recent results in methane conversion to synthesis gas by steam reforming, dry reforming, autothermal reforming and catalytic partial oxidation are presented. The high temperature methane conversion to hydrogen cyanide via the BMA-process and the Andrussow-process is considered as well. The second part of this review focuses on one-step conversion of methane into chemicals. This includes the oxidative coupling of methane to ethylene mediated by oxygen and sulfur, the direct oxidation of methane to formaldehyde and methanol, the halogenation and oxy-halogenation of methane to methyl chloride and methyl bromide and finally the non-oxidative methane aromatization to benzene and related aromates. Opportunities and limits of the various activation strategies are discussed. .

478 citations


Journal ArticleDOI
TL;DR: In this article, the authors show how the presence or absence of the Zn promoter dramatically changes not only the activity, but also unexpectedly the reaction mechanism itself, and propose two different sites for methanol synthesis, Zn-promoted and unpromoted.
Abstract: Methanol, an important chemical, fuel additive, and precursor for clean fuels, is produced by hydrogenation of carbon oxides over Cu-based catalysts. Despite the technological maturity of this process, the understanding of this apparently simple reaction is still incomplete with regard to the reaction mechanism and the active sites. Regarding the latter, recent progress has shown that stepped and ZnOx-decorated Cu surfaces are crucial for the performance of industrial catalysts. Herein, we integrate this insight with additional experiments into a full microkinetic description of methanol synthesis. In particular, we show how the presence or absence of the Zn promoter dramatically changes not only the activity, but unexpectedly the reaction mechanism itself. The Janus-faced character of Cu with two different sites for methanol synthesis, Zn-promoted and unpromoted, resolves the long-standing controversy regarding the Cu/Zn synergy and adds methanol synthesis to the few major industrial catalytic processes that are described on an atomic level.

388 citations


Journal ArticleDOI
TL;DR: Fast electrosynthesis of Fe-containing layered double hydroxide arrays and their highly-efficient electrocatalytic performance toward small molecule oxidation reactions.
Abstract: A new electrochemical synthesis route was developed for the fabrication of Fe-containing layered double hydroxide (MFe-LDHs, M = Ni, Co and Li) hierarchical nanoarrays, which exhibit highly-efficient electrocatalytic performances for the oxidation reactions of several small molecules (water, hydrazine, methanol and ethanol). Ultrathin MFe-LDH nanoplatelets (200–300 nm in lateral length; 8–12 nm in thickness) perpendicular to the substrate surface are directly prepared within hundreds of seconds (<300 s) under cathodic potential. The as-obtained NiFe-LDH nanoplatelet arrays display promising behavior in the oxygen evolution reaction (OER), giving rise to a rather low overpotential (0.224 V) at 10.0 mA cm−2 with largely enhanced stability, much superior to previously reported electro-oxidation catalysts as well as the state-of-the-art Ir/C catalyst. Furthermore, the MFe-LDH nanoplatelet arrays can also efficiently catalyze several other fuel molecules’ oxidation (e.g., hydrazine, methanol and ethanol), delivering a satisfactory electrocatalytic activity and a high operation stability. In particular, this preparation method of Fe-containing LDHs is amenable to fast, effective and large-scale production, and shows promising applications in water splitting, fuel cells and other clean energy devices.

340 citations


Journal ArticleDOI
TL;DR: This Communication describes the hydrogenation of carbon dioxide to methanol via tandem catalysis with dimethylamine and a homogeneous ruthenium complex and proposes to play a dual role in this system.
Abstract: This Communication describes the hydrogenation of carbon dioxide to methanol via tandem catalysis with dimethylamine and a homogeneous ruthenium complex. Unlike previous examples with homogeneous catalysts, this CO2-to-CH3OH process proceeds under basic reaction conditions. The dimethylamine is proposed to play a dual role in this system. It reacts directly with CO2 to produce dimethylammonium dimethylcarbamate, and it also intercepts the intermediate formic acid to generate dimethylformamide. With the appropriate selection of catalyst and reaction conditions, >95% conversion of CO2 was achieved to form a mixture of CH3OH and dimethylformamide.

334 citations


Journal ArticleDOI
TL;DR: In this paper, a detailed mechanistic study using DFT calculations shows that a sequential series of hydride transfer and protonolysis steps can account for the transformation of CO2 via formate/formic acid to hydroxymethanolate or formaldehyde and finally methanolate/methanol within the coordination sphere of a single Ru-Triphos-fragment.
Abstract: The hydrogenation of CO2 to methanol can be achieved using a single molecular organometallic catalyst. Whereas homogeneous catalysts were previously believed to allow the hydrogenation only via formate esters as stable intermediates, the present mechanistic study demonstrates that the multistep transformation can occur directly on the Ru–Triphos (Triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane) centre. The cationic formate complex [(Triphos)Ru(η2-O2CH)(S)]+ (S = solvent) was identified as the key intermediate, leading to the synthesis of the analogous acetate complex as a robust and stable precursor for the catalytic transformation. A detailed mechanistic study using DFT calculations shows that a sequential series of hydride transfer and protonolysis steps can account for the transformation of CO2via formate/formic acid to hydroxymethanolate/formaldehyde and finally methanolate/methanol within the coordination sphere of a single Ru–Triphos-fragment. All experimental results of the systematic parameter optimisation are fully consistent with this mechanistic picture. Based on these findings, a biphasic system consisting of H2O and 2-MTHF was developed, in which the active cationic Ru-complex resides in the organic phase for recycling and methanol is extracted with the aqueous phase.

280 citations


Journal ArticleDOI
TL;DR: The use of size-selected Cu4 clusters supported on Al2O3 thin films for CO2 reduction in the presence of hydrogen suggests that small Cu clusters may be excellent and efficient catalysts for the recycling of released CO2.
Abstract: The activation of CO2 and its hydrogenation to methanol are of much interest as a way to utilize captured CO2. Here, we investigate the use of size-selected Cu4 clusters supported on Al2O3 thin films for CO2 reduction in the presence of hydrogen. The catalytic activity was measured under near-atmospheric reaction conditions with a low CO2 partial pressure, and the oxidation state of the clusters was investigated by in situ grazing incidence X-ray absorption spectroscopy. The results indicate that size-selected Cu4 clusters are the most active low-pressure catalyst for catalytic CO2 conversion to CH3OH. Density functional theory calculations reveal that Cu4 clusters have a low activation barrier for conversion of CO2 to CH3OH. This study suggests that small Cu clusters may be excellent and efficient catalysts for the recycling of released CO2.

277 citations


Journal ArticleDOI
TL;DR: In this paper, the physicochemical properties of the synthesized catalysts were studied by various techniques such as differential thermal analysis/thermogravimetric analysis (DTA-TGA), BET surface area, X-ray diffraction (XRD), temperature programmed desorption of CO 2 (TPD-CO 2 ), energy dispersive Xray (EDX) spectroscopy.

266 citations


Journal ArticleDOI
TL;DR: In this paper, a ZSM-5 based catalyst with surface modification of SiO2 was used to increase the selectivity of para-xylene in xylene (X) in the methanol-to-aromatics process.
Abstract: We report a ZSM-5 based catalyst with surface modification of SiO2 to increase the selectivity of para-xylene (PX) in xylene (X) in the methanol-to-aromatics process. The effect of acid strength and acid amount in HZSM-5, Zn/P/ZSM-5, and Zn/P/Si/ZSM-5 on the catalytic performance, including methanol conversion, aromatic yield, and PX selectivity, were studied. The total acid strength and acid amount of the catalyst were crucial for high methanol conversion (around 100%) and high yield of aromatics (>60%), whereas weak external acid sites present in a small amount played an important role in increasing the PX selectivity (in the X isomers) from the usual 23–24% to 89.6%. The results validated the use of a catalyst having a core with strong acid sites in a large amount and an external shell with weak acid sites in a small amount. The contribution of the external surface reaction, including alkylation, isomerization, and dealkylation, to the PX selectivity was evaluated by using PX or ortho-X separately as f...

254 citations


Journal ArticleDOI
TL;DR: The results suggested a promising route based on economical and sustainable biomass towards the development and engineering of value-added carbon materials as effective metal-free cathode catalysts for alkaline fuel cells.
Abstract: Biomass-derived nitrogen self-doped porous carbon was synthesized by a facile procedure based on simple pyrolysis of water hyacinth (eichhornia crassipes) at controlled temperatures (600-800 °C) with ZnCl2 as an activation reagent. The obtained porous carbon exhibited a BET surface area up to 950.6 m(2) g(-1), and various forms of nitrogen (pyridinic, pyrrolic and graphitic) were found to be incorporated into the carbon molecular skeleton. Electrochemical measurements showed that the nitrogen self-doped carbons possessed a high electrocatalytic activity for ORR in alkaline media that was highly comparable to that of commercial 20% Pt/C catalysts. Experimentally, the best performance was identified with the sample prepared at 700 °C, with the onset potential at ca. +0.98 V vs. RHE, that possessed the highest concentrations of pyridinic and graphitic nitrogens among the series. Moreover, the porous carbon catalysts showed excellent long-term stability and much enhanced methanol tolerance, as compared to commercial Pt/C. The performance was also markedly better than or at least comparable to the leading results in the literature based on biomass-derived carbon catalysts for ORR. The results suggested a promising route based on economical and sustainable biomass towards the development and engineering of value-added carbon materials as effective metal-free cathode catalysts for alkaline fuel cells.

252 citations


Journal ArticleDOI
TL;DR: In this article, the authors synthesize ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition.
Abstract: In the search for alternatives to conventional Pt electrocatalysts, we have synthesized ultrathin, ternary PtRuFe nanowires (NW), possessing different chemical compositions in order to probe their CO tolerance as well as electrochemical activity as a function of composition for both (i) the methanol oxidation reaction (MOR) and (ii) the formic acid oxidation reaction (FAOR). As-prepared ‘multifunctional’ ternary NW catalysts exhibited both higher MOR and FAOR activity as compared with mono-metallic Pt NWs, binary Pt7Ru3 and Pt7Fe3 NWs, and commercial catalyst control samples. In terms of synthetic novelty, we utilized a sustainably mild, ambient wet-synthesis method never previously applied to the fabrication of crystalline, pure ternary systems in order to fabricate ultrathin, homogeneous alloy PtRuFe NWs with a range of controlled compositions. These NWs were subsequently characterized using a suite of techniques including XRD, TEM, SAED, and EDAX in order to verify not only the incorporation of Ru and Fe into the Pt lattice but also their chemical homogeneity, morphology, as well as physical structure and integrity. Lastly, these NWs were electrochemically tested in order to deduce the appropriateness of conventional explanations such as (i) the bi-functional mechanism as well as (ii) the ligand effect to account for our MOR and FAOR reaction data. Specifically, methanol oxidation appears to be predominantly influenced by the Ru content, whereas formic acid oxidation is primarily impacted by the corresponding Fe content within the ternary metal alloy catalyst itself.

Journal ArticleDOI
TL;DR: In this paper, a thermocatalytic process for the depolymerization of lignin in supercritical ethanol over a CuMgAlOx catalyst is described.

Journal ArticleDOI
TL;DR: In this article, an inverse kinetic isotope effect of H/D substitution was observed, which is stronger for methanol synthesis than for CO formation suggesting that the two reactions do not share a common intermediate.

Journal ArticleDOI
TL;DR: In this paper, the performance of ZnO and Cu 2 O/ZnO surfaces in a filter-press electrochemical cell for the continuous electroreduction of CO 2 into methanol was examined.
Abstract: In this study, we examine the performance of Cu 2 O and Cu 2 O/ZnO surfaces in a filter-press electrochemical cell for the continuous electroreduction of CO 2 into methanol The electrodes are prepared by airbrushing the metal particles onto a porous carbon paper and then are electrochemically characterized by cyclic voltammetry analyses Particular emphasis is placed on evaluating and comparing the methanol production and Faradaic efficiencies at different loadings of Cu 2 O particles (05, 1 and 18 mg cm −2 ), Cu 2 O/ZnO weight ratios (1:05, 1:1 and 1:2) and electrolyte flow rates (1, 2 and 3 ml min −1 cm −2 ) The electrodes including ZnO in their catalytic surface were stable after 5 h, in contrast with Cu 2 O-deposited carbon papers that present strong deactivation with time The maximum methanol formation rate and Faradaic efficiency for Cu 2 O/ZnO (1:1)-based electrodes, at an applied potential of −13 V vs Ag/AgCl, were r = 317 × 10 −5 mol m −2 s −1 and FE = 177 %, respectively Consequently, the use of Cu 2 O–ZnO mixtures may be of application for the continuous electrochemical formation of methanol, although further research is still required in order to develop highly active, selective and stable catalysts the electroreduction of CO 2 to methanol

Journal ArticleDOI
TL;DR: In this paper, the superior catalytic activity of In2O3 for CO2 hydrogenation to methanol is demonstrated, and the experimental results demonstrate that the reaction temperature and pressure have a significant influence on methenol yield.
Abstract: The superior catalytic activity of In2O3 for CO2 hydrogenation to methanol is demonstrated here. The experimental results demonstrate that the reaction temperature and pressure have a significant influence on methanol yield. The conversion of CO2 over In2O3 increases with the increase of reaction temperature and pressure. The yield and formation rate of methanol also increase with the increase of reaction pressure. However, they increase firstly with the increase of reaction temperature but start to decrease when the temperature rises above 330 °C. At 330 °C and 4 MPa, the yield of methanol reaches 2.82%, while the methanol production rate reaches 3.69 mol h−1 kgcat−1, higher than many other reported catalysts, which normally show very low selectivity of methanol at such high temperature. This confirms the previous theoretical study that In2O3 inhibits the reverse water gas shift, a competitive endothermic reaction for methanol synthesis from CO2 hydrogenation. The mechanism for CO2 hydrogenation to methanol over In2O3 catalyst has been discussed.

Journal ArticleDOI
TL;DR: This communication reports the discovery of several small-pore Cu-zeolites and zeotypes that produce methanol from methane and water vapor, and produce more meethanol per copper atom than Cu-ZSM-5 and Cu-mordenite.

Journal ArticleDOI
TL;DR: In this article, an experimental approach for upgrading lignin that has been isolated from corn stover via biomass fractionation using γ-valerolactone (GVL) as a solvent was demonstrated.
Abstract: We demonstrate an experimental approach for upgrading lignin that has been isolated from corn stover via biomass fractionation using γ-valerolactone (GVL) as a solvent. This GVL-based approach can be used in parallel with lignin upgrading to produce soluble carbohydrates at high yields (≥70%) from biomass without the use of enzymes, ionic liquids, or concentrated acids. The lignin was isolated after an initial hydrolysis step in which corn stover was treated in a high-solids batch reactor at 393 K for 30 min in a solvent mixture consisting of 80 wt% GVL and 20 wt% water. Lignin was isolated by precipitation in water and characterized by 2D HSQC NMR, showing that the extracted lignin was similar to native lignin, which can be attributed to the low acid level and the low extraction temperatures that are achievable using GVL as a solvent. This lignin was upgraded using a two-stage hydrogenolysis process over a Ru/C catalyst. The isolated lignin was first dissolved to form a mixture of 10% lignin, 80% THF, 8.5% H3PO4 and 1.5% H2O, and treated at 423 K under hydrogen. The THF was removed by evaporation and replaced with heptane, forming a biphasic mixture. This mixture was then treated at 523 K in the presence of Ru/C and H2. The resulting heptane phase contained soluble lignin-derived monomers corresponding to 38% of the carbon in the original lignin. By adding 5% methanol during the second catalytic step, we produced additional monomers containing methyl esters and increased carbon yields to 48%. This increase in yield can be attributed to stabilization of carboxylic acid intermediates by esterification. The yield reported here is comparable to yields obtained with native lignin and is much higher than yields obtained with lignin isolated by other processes. These results suggest that GVL-based biomass fractionation could facilitate the integrated conversion of all three biomass fractions.

Journal ArticleDOI
TL;DR: The results clearly indicate that Cu2O remains at the surface of the catalyst and it efficiently catalyzes the conversion process of CO2 at low overpotential, exhibiting a high selective faradaic efficiency of over 20% towards C2H4 formation even in long-term electrolysis.
Abstract: Electrochemical conversion of carbon dioxide (CO2) to small organic fuels (e.g. formate, methanol, ethylene, ethanol) is touted as one of the most promising approaches for solving the problems of climate change and energy security. In this study, we report the highly efficient electrochemical reduction of CO2 using cuprous oxide (Cu2O) electrodes to produce ethylene (C2H4) primarily. During CO2 electrolysis using electrodeposited Cu2O on a carbon electrode, we observe the transformation of a compact metal oxide layer to a metal oxide structure with oxygen vacant sites at the bulk region. In contrast to previous studies, our results clearly indicate that Cu2O remains at the surface of the catalyst and it efficiently catalyzes the conversion process of CO2 at low overpotential, exhibiting a high selective faradaic efficiency of over 20% towards C2H4 formation even in long-term electrolysis.

Journal ArticleDOI
TL;DR: In this article, the impact of the solvent choice on pulp retention and delignification efficiency was investigated in the Pd/C-catalyzed reductive liquid processing of birch wood.

Journal ArticleDOI
TL;DR: In this article, the synthesis of a heterogeneous catalyst (KBr/CaO) from commercial calcium oxide and potassium bromide by wet impregnation method was tested for transesterification of waste cooking oil (WCO).

Journal ArticleDOI
TL;DR: In this paper, a pincer-supported Fe compound and a co-catalytic amount of a Lewis acid were used to catalyze base-free aqueous phase methanol dehydrogenation with turnover numbers up to 51,000.
Abstract: Hydrogen is an attractive alternative energy vector to fossil fuels if effective methods for its storage and release can be developed. In particular, methanol, with a gravimetric hydrogen content of 12.6%, is a promising target for chemical hydrogen storage. To date, there are relatively few homogeneous transition metal compounds that catalyze the aqueous phase dehydrogenation of methanol to release hydrogen and carbon dioxide. In general, these catalysts utilize expensive precious metals and require a strong base. This paper shows that a pincer-supported Fe compound and a co-catalytic amount of a Lewis acid are capable of catalyzing base-free aqueous phase methanol dehydrogenation with turnover numbers up to 51 000. This is the highest turnover number reported for either a first-row transition metal or a base-free system. Additionally, this paper describes preliminary mechanistic experiments to understand the reaction pathway and propose a stepwise process, which requires metal–ligand cooperativity. This...

Journal ArticleDOI
TL;DR: In this paper, a two-step process i.e. esterification and transesterification was performed, where the ionic liquid butyl-methyl imidazolium hydrogensulfate (BMIMHSO 4 ) was found to be effective due to its longer side chain.

Journal ArticleDOI
TL;DR: Limiting oxygen concentration values, which define the minimum partial pressure of oxygen that supports a combustible mixture, have been measured for nine commonly used organic solvents at elevated temperatures and pressures to define safe operating conditions for the use of oxygen with organicsolvents.

Journal ArticleDOI
TL;DR: The present ATcT results are the most accurate thermochemical values currently available for these species.
Abstract: Active Thermochemical Tables (ATcT) thermochemistry for the sequential bond dissociations of methane, ethane, and methanol systems were obtained by analyzing and solving a very large thermochemical network (TN). Values for all possible C–H, C–C, C–O, and O–H bond dissociation enthalpies at 298.15 K (BDE298) and bond dissociation energies at 0 K (D0) are presented. The corresponding ATcT standard gas-phase enthalpies of formation of the resulting CHn, n = 4–0 species (methane, methyl, methylene, methylidyne, and carbon atom), C2Hn, n = 6–0 species (ethane, ethyl, ethylene, ethylidene, vinyl, ethylidyne, acetylene, vinylidene, ethynyl, and ethynylene), and COHn, n = 4–0 species (methanol, hydroxymethyl, methoxy, formaldehyde, hydroxymethylene, formyl, isoformyl, and carbon monoxide) are also presented. The ATcT thermochemistry of carbon dioxide, water, hydroxyl, and carbon, oxygen, and hydrogen atoms is also included, together with the sequential BDEs of CO2 and H2O. The provenances of the ATcT enthalpies o...

Journal ArticleDOI
15 Jan 2015-Fuel
TL;DR: In this article, the optimization of transesterification process parameters for the production of Manilkara Zapota Methyl Ester (MZME) has been studied and the experimental study revealed that 50°C temperature of reaction, 90min of time of reaction and 6:1 M ratio of methanol to oil and 1/wt% of concentration of catalyst are the optimal process parameters.

Journal ArticleDOI
TL;DR: In this paper, the effect of boron incorporation into H-ZSM-5 nanocatalyst on the stability, product distribution and hydrocarbons selectivity in methanol to olefins (MTO) reaction was investigated.

Journal ArticleDOI
TL;DR: In this paper, a simple method was developed for biodiesel production from non-edible Jatropha oil which contains high free fatty acid using a bifunctional acid-base catalyst.

Journal ArticleDOI
TL;DR: Recent homogeneous catalytic systems have been reported which are able to promote either one or the other of the two reactions under mild conditions, and may pave the way to a methanol based economy as part of a promising renewable energy system.

Journal ArticleDOI
TL;DR: In this paper, the photocatalytic conversion of methane into methanol from an aqueous suspension containing mesoporous WO3 was studied, as well as the effect of the addition of electron scavengers (Fe3+, Cu2+, Ag+) and H2O2 species.
Abstract: Mesoporous WO3 was synthesized by replicating technique using ordered mesoporous silica KIT-6 as the template. The obtained material exhibits high surface area (151 m2 g−1) and porous structure. The photocatalytic conversion of methane into methanol from an aqueous suspension containing mesoporous WO3 was studied, as well as the effect of the addition of electron scavengers (Fe3+, Cu2+, Ag+) and H2O2 species. In the presence of Fe3+ ions the production of methanol was about two and a half times higher than that of pure mesoporous WO3, which was principally attributed to the largely improved electron-hole separation in this system. However, the CO2 generation rates were also increased, mainly in the presence of Ag+ ions. It was also corroborated that extra hydroxyl radicals in the aqueous medium do not improve the generation of methanol but a noticeable increase in the formation of ethane was evidenced. This suggests that only a higher availability of HO•’s adsorbed on the catalyst can enhance the performance of methanol generation in the photocatalytic process.

Journal ArticleDOI
TL;DR: The results indicate that the Cu(II)-O-Cu(II) sites previously associated with methane oxidation in both Cu-MOR and Cu-ZSM-5 are oxidation active but carbonylation inactive.
Abstract: The selective low temperature oxidation of methane is an attractive yet challenging pathway to convert abundant natural gas into value added chemicals. Copper-exchanged ZSM-5 and mordenite (MOR) zeolites have received attention due to their ability to oxidize methane into methanol using molecular oxygen. In this work, the conversion of methane into acetic acid is demonstrated using Cu-MOR by coupling oxidation with carbonylation reactions. The carbonylation reaction, known to occur predominantly in the 8-membered ring (8MR) pockets of MOR, is used as a site-specific probe to gain insight into important mechanistic differences existing between Cu-MOR and Cu-ZSM-5 during methane oxidation. For the tandem reaction sequence, Cu-MOR generated drastically higher amounts of acetic acid when compared to Cu-ZSM-5 (22 vs 4 μmol/g). Preferential titration with sodium showed a direct correlation between the number of acid sites in the 8MR pockets in MOR and acetic acid yield, indicating that methoxy species present i...