How *CO spill-over affects C–C coupling on amorphous Cu for converting CO2 to multi-carbon products

Cu-based catalysts, especially oxide-derived Cu, exhibit high multi-carbon product selectivity, thus showing excellent industrialization prospects. Although the mechanism for the superiority is debatable, both experimental and calculation results indicate that the more disordered crystal structure is better for C–C coupling. Herein, we build an amorphous Cu model by making oxygen doping and disordered morphology to approach the actual condition. The oxygen atoms in the subsurface would diffuse to the surface, creating a vacancy that would break the C–C bond. Besides, only limited sites on the amorphous surface with low coordination number and stepped morphology are conducive to the occurrence of CO–CO coupling. Furthermore, we find that the spill-over effect on the amorphous Cu surface could promote the coupling of two *CO intermediates by reducing the reaction energy barrier rather than 50 % of the C–C coupling process on stationary positions. This beneficial strategy encourages the synthesis of C2+ products.