A study is conducted to demonstrate catalytic dehydrogenation of light alkanes on metals and metal oxides. The study provides a complete overview of the materials used to catalyze this reaction, as dehydrogenation for the production of light olefins has become extremely relevant. Relevant factors, such as the specific nature of the active sites, as well as the effect of support, promoters, and reaction feed on catalyst performance and lifetime, are discussed for each catalytic Material. The study compares different catalysts in terms of the reaction mechanism and deactivation pathways and catalytic performance. The duration of the dehydrogenation step depends on the heat content of the catalyst bed, which decreases rapidly due to the endothermic nature of the reaction. Part of the heat required for the reaction is introduced to the reactors by preheating the reaction feed, additional heat being provided by adjacent reactors that are regenerating the coked catalysts.

Catalytic dehydrogenation of light alkanes on metals and metal oxides.

The replacement of fossil resources that currently provide more than 90% of our energy needs and feedstocks of the chemical industry in combination with reduced emission of carbon dioxide is one of the most pressing challenges of mankind. Biomass as a globally available resource has been proposed as an alternative feedstock for production of basic building blocks, which could partially or even fully replace the currently utilized fossil-based ones in well-established chemical processes. The destruction of lignocellulosic feed followed by oxygen removal from its cellulose and hemicellulose content by catalytic processes results in the formation of initial platform chemicals (IPCs). However, their sustainable production strongly depends on the availability of resources, their efficient or even industrially viable conversion processes, and replenishment time of feedstocks. Herein, we overview recent advances and developments in catalytic transformations of the carbohydrate content of lignocellulosic biomass ...

Catalytic Conversion of Carbohydrates to Initial Platform Chemicals: Chemistry and Sustainability

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

Recent Advances in Dry Reforming of Methane Over Ni-Based Catalysts

The comparative catalytic activity and coke resistance are examined in carbon dioxide reforming of methane over Ni/CeO2 nanorods (NR) and nanopolyhedra (NP). The Ni/CeO2–NR catalysts display more excellent catalytic activity and higher coke resistance compared with the Ni/CeO2–NP. The high resolution transmission electron microscope reveals that the predominantly exposed planes are the unusually reactive {110} and {100} planes on the CeO2–NR rather than the stable {111} one on the CeO2–NP. The prepared samples were also characterized by X-ray diffraction, transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray photoelectron spectroscopy, UV and visible Raman spectra, and oxygen temperature-programmed oxidation. The {110} and {100} planes show great superiority for the anchoring of Ni nanoparticles, which results in the existence of strong metal–support interaction effect (SMSI). The SMSI effect can be helpful to prevent sintering of Ni particles, which benefits to reduce the dea...

Morphology Dependence of Catalytic Properties of Ni/CeO2 Nanostructures for Carbon Dioxide Reforming of Methane

Ordered mesoporous NiO-MgO-Al2O3 composite oxides with various Ni and Mg content were facilely synthesized via one pot evaporation induced self-assembly (EISA) strategy. These mesoporous materials with large specific surface areas, big pore volumes, uniform pore sizes and superior thermal stability were investigated as the catalysts for the carbon dioxide reforming of methane reaction. These materials performed high catalytic activity as well as long stability. The improved catalytic performances were suggested to be closely associated with both the amount of laccessibler active centers for the reactants owing to their advantageous structural properties and the stabilized Ni nanoparticles by mesoporous framework matrix due to the lconfinement effectr of the mesopores. Besides, the role of the MgO basic modifier was also studied. It was observed that only moderate amount of the Mg containing (2 M%) could greatly promote the catalytic performances. The stabilized Ni nanoparticles as well as doped MgO had reinforced capacity of resistance to coke, accounting for no deactivation after 100 h long-term stability test at 700 ◦C. Therefore, the ordered mesoporous NiO-MgO-Al2O3 composite oxides promised a series of novel and stable catalyst candidates for carbon dioxide reforming of methane reaction.

Carbon dioxide reforming of methane over ordered mesoporous NiO–MgO–Al2O3 composite oxides

Ordered mesoporous tricompound NiO–CaO–Al2O3 composite oxides with various Ca content were first designed and facilely synthesized via a one-pot, evaporation-induced, self-assembly (EISA) strategy. The obtained mesoporous materials with advantageous textural properties and superior thermal stabilities were investigated as the catalysts for the carbon dioxide reforming of methane reaction. These mesoporous catalysts entirely showed high catalytic activities as well as long catalytic stabilities toward this reaction. The improved catalytic activities were suggested to be closely associated with the advantageous structural properties, such as large specific surface areas; big pore volumes; and uniform pore sizes, which could provide sufficient “accessible” active centers for the gaseous reactants. In addition, the “confinement effect” of the mesoporous matrixes contributed to stabilizing the Ni active sites during the processes of reduction and reaction, accounting for the long lifetime stabilities of these ...

Lingjun Chou

Papers

Carbon dioxide reforming of methane over ordered mesoporous NiO–MgO–Al2O3 composite oxides

One-Pot Synthesis of Ordered Mesoporous NiO-CaO-Al2O3 Composite Oxides for Catalyzing CO2 Reforming of CH4

Ordered mesoporous MgO―Al2O3 composite oxides supported Ni based catalysts for CO2 reforming of CH4: Effects of basic modifier and mesopore structure

Ordered mesoporous alumina supported nickel based catalysts for carbon dioxide reforming of methane

Carbon dioxide reforming of methane over ordered mesoporous NiO–Al2O3 composite oxides