Dry (CO2) reforming of methane (DRM) is a well-studied reaction that is of both scientific and industrial importance. This reaction produces syngas that can be used to produce a wide range of products, such as higher alkanes and oxygenates by means of Fischer–Tropsch synthesis. DRM is inevitably accompanied by deactivation due to carbon deposition. DRM is also a highly endothermic reaction and requires operating temperatures of 800–1000 °C to attain high equilibrium conversion of CH4 and CO2 to H2 and CO and to minimize the thermodynamic driving force for carbon deposition. The most widely used catalysts for DRM are based on Ni. However, many of these catalysts undergo severe deactivation due to carbon deposition. Noble metals have also been studied and are typically found to be much more resistant to carbon deposition than Ni catalysts, but are generally uneconomical. Noble metals can also be used to promote the Ni catalysts in order to increase their resistance to deactivation. In order to design catalysts that minimize deactivation, it is necessary to understand the elementary steps involved in the activation and conversion of CH4 and CO2. This review will cover DRM literature for catalysts based on Rh, Ru, Pt, and Pd metals. This includes the effect of these noble metals on the kinetics, mechanism and deactivation of these catalysts.

A review of dry (CO2) reforming of methane over noble metal catalysts

Methanol-to-hydrocarbons: catalytic materials and their behavior

Although technological practice should minimize environmental impact, this is not always economically feasible. During the past decade, for example, there has been increasing global concern over th...

CO2 Reforming of CH4

Carbon dioxide reforming of methane produces synthesis gas with a low hydrogen to carbon monoxide ratio, which is desirable for many industrial synthesis processes. This reaction also has very important environmental implications since both methane and carbon dioxide contribute to the greenhouse effect. Converting these gases into a valuable feedstock may significantly reduce the atmospheric emissions of CO2 and CH4. In this paper, we present a comprehensive review on the thermodynamics, catalyst selection and activity, reaction mechanism, and kinetics of this important reaction. Recently, research has centered on the development of catalysts and the feasible applications of this reaction in industry. Group VIII metals supported on oxides are found to be effective for this reason. However, carbon deposition causing catalyst deactivation is the major problem inhibiting the industrial application of the CO2/CH4 reaction. Ni-based catalysts impregnated on certain supports show carbon-free operation and thus attract much attention. To develop an effective catalyst for CO2 reforming of CH4 and accelerate the commercial application of the reaction, the following are identified to be the most important areas for future work: (1) selection of metal and support and studying the effect of their interaction on catalyst activity; (2) the effect of different promoter on catalyst activity; (3) the reaction mechanism and kinetics; and (4) pilot reactor performance and scale-up operation.

Carbon Dioxide Reforming of Methane To Produce Synthesis Gas over Metal-Supported Catalysts: State of the Art

The role of catalyst support on the activity of nickel for reforming methane with CO2

High activities and selectivities of Ni on SiO2 catalysts producing CO in the reaction of CH4 with CO2, have been obtained at relatively low temperatures. These aspects are considerably different from the activities or selectivities of other catalysts, and have been explained by assuming that the Ni on SiO2 catalyst markedly suppresses carbon deposition.

Catalytic reaction of methane with carbon dioxide

The catalytic reaction between hydrocarbons and carbon dioxide, e.g. CH4+ +CO2→2CO+2H2 and C6H6CH3+CO2→C6H6+2CO+H2, has been investigated over various metallic catalysts under atmospheric pressure. In general, Rh−Al2O3 catalyst was found to be excellent in activity and selectivity. The reaction rates were moderately dependent on the pressure of carbon dioxide, whereas it was little influenced by the pressure of hydrocarbon.

Catalytic reactions of hydrocarbon with carbon dioxide over metallic catalysts

The Cu−SiO2 catalyst prepared by ion exchange method shows a longer life for the dehydrogenation of methanol, as compared with those of Cu catalysts prepared by other methods. This suggests that the highly dispersed Cu particles on the support cannot be easily aggregated during the reaction.

Dynamic change in surface area of Cu in dehydrogenation of methanol over Cu−SiO2 catalyst prepared by ion exchange method

Effect of supports such as SiO2, ZrO2 and TiO2 on the dehydrogenation of methanol were studied using Cu containing catalysts prepared by ion exchange. It was found that the catalytic activity, selectivity to methyl formate, and turnover frequency differ widely, depending on the support. Every catalyst showed a long life for the reaction.

Effect of support on dehydrogenation of methanol to methyl formate over Cu-containing catalysts prepared by ion exchange

The side-chain alkylation of toluene to form ethylbenzene or styrene has been investigated using a conventional flow reactor at temperatures near 475°C. Cs2O (10–20 wt. %)-activated carbon catalyst prepared by an impregnation method showed an excellent activity and selectivity. The calcination temperature of the catalyst and the addition of CO2 or H2O into the reactant mixture affected the catalyst activity in a striking manner.

T. Sodesawa

Papers

Catalytic reaction of methane with carbon dioxide

Catalytic reactions of hydrocarbon with carbon dioxide over metallic catalysts

Dynamic change in surface area of Cu in dehydrogenation of methanol over Cu−SiO2 catalyst prepared by ion exchange method

Effect of support on dehydrogenation of methanol to methyl formate over Cu-containing catalysts prepared by ion exchange

Side-chain alkylation of toluene with methanol over Cs2O-activated carbon catalyst