Simulated solar light-driven photothermal preferential oxidation of carbon monoxide in H2-rich streams over fast-synthesized CuCeO2–x nanorods

Abstract

Aiming for purification the trace amount of CO in H2-rich streams with reduced energy consumption and low cost, solar-driven photothermal preferential oxidation of carbon monoxide on the non-precious metal oxide catalyst is proposed in this work. Cu doped CuCeO2−x nanorods catalysts were synthesized with a fast and simple coprecipitation method at the room temperature, which shows high CO oxidation activity in photothermal preferential oxidation of CO (CO-PROX) under UV-Vis-IR light irradiation. Rely on the various characterization methods such as UV-Vis-IR diffuse reflection spectrum (UV-Vis-IR DRS), photoluminescence spectrum (PL), transient photocurrent test, HRTEM, XRD, XPS, UV-Raman and H2-TPR, the optical and chemical properties of the CuCeO2−x nanorods catalysts were uncovered. The photothermal catalytic activity of CuCeO2−x nanorods doped with 10 wt% Cu reaches to 90% CO conversion under Xe lamp illumination (2.5 suns), and the solar driven photothermal CO-PROX reaction on CuCeO2−x nanorods were proposed to be proceeded by the light-to-thermal conversion and subsequently to drive a thermal catalytic process. The catalytic performance of CuCeO2−x nanorods in photothermal CO-PROX is closely related to the photo-to-thermal conversion efficiency and Cu-Ce synergetic interaction of CuCeO2−x nanorods catalyst. The introduction of CuOx greatly broaden the optical absorption range and promotes the light absorption capacity of ceria nanorods, which induces the catalyst with high photo-to-thermal conversion capability. Moreover, the optimal copper dopant benefits to enhance the Cu-Ce synergetic interaction and accelerate the oxidation reaction taking place at low temperature. CuCeO2−x nanorods catalyst shows promising competitive activity and ultra-low cost compared with the noble-based catalyst for the purification of hydrogen streams by the clean and eco-friendly sunlight sources.