Water-Gas-Shift (WGS) reaction represents a crucial step in hydrogen production from fossil fuels and the performance of the current commercial catalysts used for WGS demands major improvement. Using of a combination of high-resolution scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), CO Temperature-programmed desorption (TPD) experiments, and density functional theory (DFT) calculations, we suggest the existence of a new thermodynamically stable Cu/Pt near-surface alloy (NSA), promising for WGS catalysis. DFT calculations show that this Cu/Pt NSA binds CO, formate and other reaction intermediates significantly more weakly than Cu. We also find that this Cu/Pt NSA has a low activation barrier for H2O dissociation, the rate-determining step for the WGS on several metal surfaces. Thus, this NSA is resistant to poisoning by most prominent reactive intermediates, is very active for H2O activation, and -as a result- holds promise as an improved WGS catalyst.

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