Hydrogen production for energy: An overview

This review will explore the influences of the active metal, support, promoter, preparation methods, calcination temperature, reducing environment, particle size and reactor choice on catalytic activity and carbon deposition for the dry reforming of methane Bimetallic (Ni−Pt, Ni−Rh, Ni−Ce, Ni−Mo, Ni−Co) and monometallic (Ni) catalysts are preferred for dry reforming compared to noble metals (Rh, Ru and Pt) due to their low-cost Investigation of support materials indicated that ceria−zirconia mixtures, ZrO2 with alkali metals (Mg2+, Ca2+, Y2+) addition, MgO, SBA-15, ZSM-5, CeO2, BaTiO3 and Ca08Sr02TiO3 showed improved catalytic activities and decreased carbon deposition The modifying effects of cerium (Ce), magnesium (Mg) and yttrium (Y) were significant for dry reforming of methane MgO, CeO2 and La2O3 promoters for metal catalysts supported on mesoporous materials had the highest catalyst stability among all the other promoters Preparation methods played an important role in the synthesis of smaller particle size and higher dispersion of active metals Calcination temperature and treatment duration imparted significant changes to the morphology of catalysts as evident by XRD, TPR and XPS Catalyst reduction in different environments (H2, He, H2/He, O2/He, H2−N2 and CH4/O2) indicated that probably the mixture of reducing agents will lead to enhanced catalytic activities Smaller particle size (

Dry reforming of methane: Influence of process parameters—A review

Increasing demand for sustainable chemicals and fuels has pushed academia and industry to search for alternative feedstocks replacing crude oil in traditional refineries. As a result, an immense academic attention has focused on the valorisation of biomass (components) and derived intermediates to generate valuable platform chemicals and fuels. Zeolite catalysis plays a distinct role in many of these biomass conversion routes. This contribution emphasizes the progress and potential in zeolite catalysed biomass conversions and relates these to concepts established in existing petrochemical processes. The application of zeolites, equipped with a variety of active sites, in Bronsted acid, Lewis acid, or multifunctional catalysed reactions is discussed and generalised to provide a comprehensive overview. In addition, the feedstock shift from crude oil to biomass involves new challenges in developing fields, like mesoporosity and pore interconnectivity of zeolites and stability of zeolites in liquid phase. Finally, the future challenges and perspectives of zeolites in the processing of biomass conversion are discussed.

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Potential and challenges of zeolite chemistry in the catalytic conversion of biomass

The performance of catalysts used for the dry reforming of methane can strongly depend on the selection of active metals, supports and promoters. This work studies their effects on the activity and stability of selected catalysts. Designing an economically viable catalyst that maintains high catalytic activity and stability can be achieved by exploiting the synergic effects of combining noble and/or non-noble metals to form highly active and stable bi- and tri-metallic catalysts. Perovskite type catalysts can also constitute a potent and cost effective substituent. Metal oxide supports with surface Lewis base sites are able to reduce carbon formation and yield a greater stability to the catalyst, while noble metal promoters have proven to increase both catalyst activity and stability. Moreover, a successful metal-support-promoter combination should lead to higher metal-support interacrtion, lower reduction temperature and enhancement of the anti-coking and anti-amalgamation properties of the catalyst. However, the effect of each parameter on the overall performance of the catalyst is usually complex, and the catalyst designer is often faced with a tradeoff between activity, stability and ease of activation. Based on the review carried out on various studies, it is concluded that a catalyst design must take into consideration not only the separate effects of the active metal, support and promoter, but should also include the combined and mutual interactions of these components.

Catalyst design for dry reforming of methane: Analysis review

A review on dry reforming of methane in aspect of catalytic properties

Low-temperature catalytic CO2 dry reforming of methane on Ni-based catalysts: A review

The activity of a ZrO2-supported nickel catalyst promoted by silica (Ni-Si/ZrO2) in CO2 dry reforming of methane was carried out at 400 and 450 °C. The catalysts were prepared by an impregnation method and characterized by H2-TPR, XRD, TEM, TG-MS, Raman, XPS, and in situ XPS and DRIFTS. It was discovered that Ni-Si/ZrO2 showed higher initial conversion of CH4 (0.50 s–1) and CO2 (0.44 s–1), and stability for low temperature (400 °C) DRM reaction in comparison to an SiO2-supported nickel catalyst promoted by zirconia (Ni-Zr/SiO2) (0.32 s–1 for both CO2 and CH4). The Ni-Si/ZrO2 catalyst featured the formation of active nickel particles with a small size of 6–9 nm and with slightly strong electronic donor ability, stabilization of the initial metal nickel state under the reaction conditions, and the formation of easily removed C1 coke. However, for the 450 °C DRM reaction, the coke that formed on the Ni-Si/ZrO2 catalyst was mainly C2 coke that was difficult to remove, because the CO2 preferred to combine with...

Low-Temperature Catalytic CO2 Dry Reforming of Methane on Ni-Si/ZrO2 Catalyst

The promoting effect of La, Mg, Co and Zn on the activity and stability of Ni/SiO2 catalyst for CO2 reforming of methane

Comparative study on the promotion effect of Mn and Zr on the stability of Ni/SiO2 catalyst for CO2 reforming of methane

We have synthesized the nickel phosphides supported on the commercial HZSM-22 catalysts, which were used to convert palmitic acid to diesel-like hydrocarbons under ambient pressure in the absence of any solvents. The deoxygenation reactions of palmitic acid were studied in a fixed-bed reactor over HZSM-22, Ni x P/HZSM-22, Ni 2 P/HZSM-22, the unsupported Ni x P and the unsupported Ni 12 P 5 catalysts. The conversion of palmitic acid and the hydrocarbon yield were found to be 99.6% and 42.9%, respectively, for the best catalyst, 40 Ni x P/HZSM-22. The heat value of the resulting hydrocarbons was 46.4 MJ kg −1 . Ketones and aldehydes were identified as reaction intermediates, which were subsequently converted into hydrocarbons. In addition, short-chain hydrocarbons and aromatic hydrocarbons were generated, suggesting the presence of cracking and isomerization reactions. Our mechanistic exploration and the NH 3 adsorption–desorption DRIFT spectra suggest that the decarbonylation and decarboxylation are facilitated by Ni x P, whereas Bronsted acid sites on HZSM-22 play a crucial role in the isomerization reactions and Lewis acids sites on catalysts are responsible for the cracking reactions. The present study demonstrates that the catalysts such as Ni x P supported on commercial HZSM-22 can serve as a practical modus with excellent catalytic activity to produce diesel-like hydrocarbons from biomass-based oil.

Lu Yao

Papers

Low-temperature catalytic CO2 dry reforming of methane on Ni-based catalysts: A review

Low-Temperature Catalytic CO2 Dry Reforming of Methane on Ni-Si/ZrO2 Catalyst

The promoting effect of La, Mg, Co and Zn on the activity and stability of Ni/SiO2 catalyst for CO2 reforming of methane

Comparative study on the promotion effect of Mn and Zr on the stability of Ni/SiO2 catalyst for CO2 reforming of methane

The production of diesel-like hydrocarbons from palmitic acid over HZSM-22 supported nickel phosphide catalysts