Reactor Design for CO 2 Photo-Hydrogenation toward Solar Fuels under Ambient Temperature and Pressure

摘要

Photo-hydrogenation of carbon dioxide (CO 2 ) is a green and promising technology and has received much attention recently. This technique could convert solar energy under ambient temperature and pressure into desirable and sustainable solar fuels, such as methanol (CH 3 OH), methane (CH 4 ), and formic acid (HCOOH). It is worthwhile to mention that this direction can not only potentially depress atmospheric CO 2 , but also weaken dependence on fossil fuel. Herein, 1 wt % Pt/CuAlGaO 4 photocatalyst was successfully synthesized and fully characterized by ultraviolet-visible light (UV-vis) spectroscopy, X-ray diffraction (XRD), Field emission scanning electron microscopy using energy dispersive spectroscopy analysis (FE-SEM/EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET), respectively. Three kinds of experimental photo-hydrogenation of CO 2 in the gas phase, liquid phase, and gas-liquid phase, correspondingly, were conducted under different H 2 partial pressures. The remarkable result has been observed in the gas-liquid phase. Additionally, increasing the partial pressure of H 2 would enhance the yield of product. However, when an extra amount of H 2 is supplied, it might compete with CO 2 for occupying the active sites, resulting in a negative effect on CO 2 photo-hydrogenation. For liquid and gas-liquid phases, CH 3 OH is the major product. Maximum total hydrocarbons 8.302 μmol·g ?1 is achieved in the gas-liquid phase.