Hydrogen energy has become an important research area worldwide for environmental-friendly and sustainable energy development. A large number of studies can be found in the literature regarding the development of novel functional catalysts for hydrogen production from various reactions such as hydrocarbon reforming, water gas shift reaction, and water decomposition reaction. Due to the unique surface and electronic properties of molybdenum carbide, it has been attracted more and more attentions as a potential catalyst. This article reviews the latest research progress on the molybdenum carbide catalyst for hydrogen production. Two main parts are included in this review: preparation of molybdenum carbide and application of it in hydrogen production technology. In the first part, various molybdenum carbide preparation methods and the strategies to modify the physicochemical properties of molybdenum carbide are described. It is concluded that solid-solid reaction method could provide high surface area and the synthesis process is relatively easy and safe. Furthermore, the addition of second metal could increase molybdenum carbide surface area and adjust catalyst surface electronic condition. In the second part, the applications of molybdenum carbide based catalysts for various reactions for hydrogen production are described. The catalytic activity, stability, and deactivation and reaction mechanism over molybdenum carbide catalyst are critically reviewed and discussed. It indicates that molybdenum carbide should be an alternative catalyst with high efficiency for hydrogen production.

Molybdenum carbide as alternative catalyst for hydrogen production – A review

Methane reforming reaction with carbon dioxide over SBA-15 supported Ni–Mo bimetallic catalysts

Dry (CO2) reforming of methane (DRM) for syngas production, a critical feedstock for the production of hydrogen, ammonia, and Fischer-Tropsch derived liquid energy carriers, unequivocally ranks among the top issues of applied catalysis in the light of environmental protection, renewable energy production and circular economy. This mainly because DRM involves the simultaneous reduction of two key greenhouse gases (CO2 and CH4) and provides an efficient way for CO2 utilization/recycling and the direct implementation of biogas. The same advantages make DRM a more favorable process compared to steam- or oxi- reforming ones. The design of cost-effective, efficient and robust (coking- and sintering-resistant) DRM catalysts is a grand challenge in the topic. Bimetallic catalysts, providing synergistic effects via metal-to-metal interactions seem to be an effective strategy for achieving these goals. A review of the recent literature achievements on DRM using bimetallic catalyst formulations is provided herein in a comprehensive and comparative manner.

A review of recent efforts to promote dry reforming of methane (DRM) to syngas production via bimetallic catalyst formulations

Cobalt-modified molybdenum carbide as an efficient catalyst for chemoselective reduction of aromatic nitro compounds

Dry reforming of methane with CO 2 (DRM) was studied over Ni–Mo 2 C catalysts with Ni/Mo molar ratios of 1/3, 1/2, and 1/1 (denoted as Ni–Mo 2 C (1/3), Ni–Mo 2 C (1/2), and Ni–Mo 2 C (1/1), respectively) aiming to investigate the catalytic roles of Ni and the carbide. The results of XRD and XPS characterizations indicated that the carbonization process was promoted by the presence of Ni. The CH 4 -TPR and CO 2 -TPO over the fresh samples proved that CH 4 dissociation was greatly enhanced by Ni. The Ni–Mo 2 C (1/2) catalyst showed the best catalytic activity and stability for CH 4 /CO 2 (1/1) dry reforming. Above 80% of CH 4 and CO 2 conversions were maintained at 800 °C during a test run of 20 h at W/F = 0.3 g s cm −3 . Characterizations of the spent samples revealed that the deactivation of Ni–Mo 2 C (1/1) was due to coke formation whereas that of Ni–Mo 2 C (1/3) was due to bulk oxidation of Mo 2 C into MoO 2 . Only at a Ni/Mo molar ratio of 1/2, a catalytic oxidation–reduction cycle could be established. It was suggested that Ni–Mo 2 C was a typical bi-functional catalyst. In CH 4 /CO 2 dry reforming, the dissociation of CH 4 was catalyzed by Ni, while the activation of CO 2 took place on Mo 2 C. By regulating the molar ratio of Ni and Mo 2 C, a catalytic redox cycle could be established.

Jinmin Cheng

Papers

Effect of cobalt (nickel) content on the catalytic performance of molybdenum carbides in dry-methane reforming