Optimizing Mo-C coordination for enhanced low-temperature water-gas shift activity over α-MoC1-x catalysts: An experimental and theoretical study

The low-temperature water-gas shift (WGS) reaction is an important industrial process for producing hydrogen and reducing carbon dioxide emissions. The alpha-MoC(1-x )catalysts have shown promising performance in WGS reactions, but their activities are highly dependent on the surface structure. In this study, we investigated the effect of surface Mo and C ordinations on the low-temperature WGS activity of Pt/alpha-MoC1-x catalysts using both experimental and theoretical methods. Our results reflected that as Mo: C ratio decreases, the surface free carbon and reduced number of Mo active sites led to a weakened electron transfer ability, resulting in poor catalytic activity. The 0.4% Pt/alpha-MoC1-x -50 catalyst displayed superior hydrogen production activity and low apparent activation energy (E-app = 58.5 kJ/mol) at low temperatures (100-200 C-degrees). Our density functional theory (DFT) calculations revealed that the high reactivity of the 0.4% Pt/alpha-MoC1-x -50 catalyst was due to the strong electron transfer capability and increased number of surface Mo active sites. This study provides new insights into the structure-activity relationship and stability of alpha-MoC(1-x )fcatalysts for the WGS reaction and lays the foundation for the design of WGS catalysts with high activity and stability at low temperature.

Automated summary

The effect of surface Mo and C coordination on the low-temperature WGS activity of Pt/alpha-MoC1-x catalysts was investigated. The study found that a decrease in the Mo:C ratio led to a weakened electron transfer ability and decreased catalytic activity. The 0.4% Pt/alpha-MoC1-x -50 catalyst exhibited superior hydrogen production activity and low apparent activation energy at low temperatures.