Photothermal Conversion of CO<sub>2</sub> with Tunable Selectivity Using Fe-Based Catalysts: From Oxide to Carbide
Chuqiao Song, Xi Liu, Ming Xu, Daniel Masi, Yigui Wang, Yuchen Deng, Mengtao Zhang, Xuetao Qin, Kai Feng, Jie Yan, Jing Leng, Zhaohua Wang, Yao Xü, Binhang Yan, Shengye Jin, Dongsheng Xu, Zhen Yin, Dequan Xiao, Ding Ma
Abstract
Conversion of CO2 into fuels via solar energy would be a promising strategy to reduce CO2 emissions and produce value-added carbon compounds. However, the development of efficient light-harvesting and photocatalytic systems remains a significant challenge because of scarcity of low-cost and high-efficiency catalysts in CO2 conversion. Herein, a tunable selectivity in photothermal CO2 conversion was demonstrated over a series of Fe-based catalysts developed through a simple hydrogenation/carbonization treatment with commercial Fe3O4 as a precursor. The Fe3O4 catalyst demonstrated a full selectivity toward CO (about 100%) and 11.3 mmol g–1 h–1 activity for the photothermal catalytic conversion of CO2. More importantly, the pure-phase θ-Fe3C produced remarkably high selectivity toward hydrocarbon products (>97%) and superior activity (10.9 mmol g–1 h–1) in the photothermal conversion of CO2. Meanwhile, it is found that the selectivity toward a hydrocarbon (CHx) can be modulated by the extent of hydrogenation/carbonization of the Fe3O4 precursor. In addition, we demonstrated the vital influence of the nonthermal effect on the enhanced catalytic performance with the Fe-based catalysts during the photothermal conversion of CO2.