PtCu alloy cocatalysts for efficient photocatalytic CO2 reduction into CH4 with 100% selectivity

In this paper, PtCu alloys with varying Pt/Cu ratios were deposited onto TiO2 nanocrystals to selectively photoreduce CO2 into CH4. The experimental results show that the appropriate Pt/Cu deposition ratio significantly improves CH4 production with 100% selectivity. The PtCu alloy not only effectively promotes the separation/transfer of photogenerated charges, but is also beneficial for the adsorption of CO2 and the formation and activation of intermediates (CO2-, *COOH, *CO, and *CHO). Furthermore, two paths for *CO formation are observed on the surface of PtCu/TiO2, providing sufficient *CO for CH4 generation. Density functional theory calculations show that the synergistic effect of PtCu reduces the activation energy barriers of *CO2 and *CHO and inhibits the desorption of *CO, which simultaneously optimizes the efficiency and selectivity of CO2 reduction. These findings may provide new insights for exploring alloy cocatalysts for regulating the product selectivity of photocatalytic CO2 reduction.

Automated summary

In this study, PtCu alloys were deposited onto TiO2 nanocrystals to selectively convert CO2 into CH4 through photocatalysis. The results showed that the Pt/Cu deposition ratio significantly influenced the CH4 production and selectivity. PtCu alloys not only facilitated the separation and transfer of photogenerated charges, but also promoted the adsorption of CO2 and the formation and activation of intermediates. Additionally, density functional theory calculations revealed that the synergistic effect of PtCu reduced energy barriers and enhanced the efficiency and selectivity of CO2 reduction.