Controlled Synthesis of Cu<sup>0</sup>/Cu<sub>2</sub>O for Efficient Photothermal Catalytic Conversion of CO<sub>2</sub> and H<sub>2</sub>O
Yuke Zheng, Li Zhang, Jian Guan, Shuya Qian, Zhaoxia Zhang, Chee Keong Ngaw, Shaolong Wan, Shuai Wang, Jingdong Lin, Yong Wang
Abstract
Sustainable conversion of CO2 and H2O to fuels using solar energy is highly attractive for clean fuel production. This work focuses on the one-pot synthesis of bifunctional Cu0/Cu2O catalysts for the photothermal conversion of CO2 and H2O. The experimental results show that the Cu0/Cu2O catalysts with a Cu0/Cu2O interface and a controllable ratio of Cu0 to Cu2O can be readily synthesized by tuning the ratio of the Cu precursor to the reductant (N2H4). The activity of the prepared Cu0/Cu2O catalysts in the photothermal catalytic conversion of CO2 and H2O is greatly influenced by the ratio of Cu0 to Cu2O and the reaction temperature. Cu0/Cu2O-R2, a catalyst prepared with a Cu precursor to N2H4 ratio of 1:2, exhibited the highest activity, i.e., 13.2 μmol g–1 h–1 of CO and 2.6 μmol g–1 h–1 of CH3OH at 383 K, which is much higher than those of Cu2O or Cu. Such enhanced performance is attributed to the formation of the interface between Cu0 and Cu2O, which is beneficial not only to photocatalysis but also to thermocatalytic CO2 hydrogenation. This work illustrates that a bifunctional catalyst with mixed metal oxidation states can be prepared by a one-pot method and is efficient for improving the performance of the directly coupled photothermal catalytic conversion of CO2 and H2O.