Improving the Performance of a Co-CeO₂ Catalyst for Hydrogen Production via Water Gas Shift Reaction by Addition of Transition Metal Oxides

Abstract

The hydrogen production from combustible waste is attracting attention because of the increasing interest in clean and renewable hydrogen production. To produce hydrogen from combustible waste, gasification and water gas shift reaction processes are required. Syngas, which mainly consists of hydrogen and carbon monoxide, is generated by gasification of combustible waste. The water gas shift reaction is applied to produce additional hydrogen from carbon monoxide in waste-derived syngas. The performance of catalysts is important to achieve reasonable process efficiency. Co-based catalysts were applied to the water gas shift reaction because Co has significant capability for CO oxidation and high reaction rates when it is used as an active metal. However, it was necessary to enhance the stability of Cobased catalysts. Here, different transition metal oxides (TiO 2 , ZrO 2 , V 2 O 5 , and Nb 2 O 5 ) are used as promoters to enhance the Co-CeO 2 catalyst performance. To investigate the effects of promoters on the catalytic performance, various properties are characterized. According to the analysis results, the physicochemical properties, which determine the catalytic performance, were influenced by the addition of transition metal oxides. Among the synthesized catalysts, the Nb 2 O 5 -promoted Co-CeO 2 catalyst exhibited the best catalytic performance. As a result, the Nb 2 O 5 promoter is the most effective to improve the catalytic activity and stability of the Co-CeO 2 catalyst for high-temperature water gas shift reaction to produce hydrogen from waste-derived syngas. The higher CO conversion is related to the numerous oxygen vacancies and high Co dispersion, while stability is related to strong interactions between Co and the support. These findings are expected to aid the development of catalysts by confirming physicochemical properties relating with catalytic performance.

A System-Level Analysis for Long-Distance Hydrogen Transport Using Liquid Organic Hydrogen Carriers (LOHCs): A Case Study in Australia–Korea

“…Hydrogen is a promising candidate as an energy carrier because of its cleanliness, abundance, and high gravimetric energy density (120 MJ/kg) compared to other energy sources. , However, there are still considerations, such as its low volumetric energy density (10.9 kJ/L) and gaseous state at room conditions, for the transition to a hydrogen economy . These drawbacks make hydrogen transport difficult.…”