The catalytic applications of micron Cu powder are limited due to its large particle size and small specific surface area. Modifying micro-Cu powder to achieve a high catalytic performance is a challenge in the application of micron copper. In this work, micro-Cu was used to synthesize a CeO2–Cu catalyst, and the phase composition and surface pore structure were analyzed using XRD, BET, etc. The CO2hydrogenation performance of the CeO2–Cu catalyst was analyzed in comparison with CeO2and Cu, and we found that the CeO2–Cu catalyst exhibited a synergistic effect between Cu and cerium, resulting in a much higher hydrogenation performance at 500 °C than CeO2or Cu alone. H2-TPR and TEM characterization revealed that the CeO2–Cu catalyst formed interfacial interactions with a relatively large Ce–Cu interface, where cerium oxide could promote the reduction of CuO and lower the reduction temperature. Additionally, cerium oxide formed a confinement structure for Cu, and the CeO2–Cu catalyst exhibited a higher oxygen vacancy concentration, thereby promoting the CO2hydrogenation performance. Cu–CeO2interaction provides valuable insights into the catalytic application of micron Cu powder.
Cu-based catalysts had been widely used in CO 2 hydrogenation process for their excellent performance and high selectivity. Micron-sized Cu powder obtained by ball milling exhibited poor CO 2 activity for its large particle size and small specific surface area, limited its catalytic application. In this work, micron Cu powder was modified with CeO 2 species synthesized from different cerium precursor salts via a solution auto-combustion method to investigate CO 2 hydrogenation activity. This work revealed that CeO 2 species formed from cerium acetate precursor salt achieved excellent CO 2 performance (1.64 mol/g cat .h at 400 °C), which was 3.8 times and 6000 times higher than that from cerium nitrate salt or cerium chloride salt, respectively. Interestingly, a thick dense CeO 2 shell would be formed on micron Cu generated from cerium(III) chloride precursor salt, which inhibited CuO x reduction and had the opposite effect for RWGS reaction. In addition, the CuO x species in CeO 2 @Cu synthesized from cerium chloride salt resulted in the CH 4 selectivity. The enhancement performance of the CeO 2 @Cu prepared from cerium acetate salt and cerium nitrate salt could be attributed to the oxygen defects formed around the Cu-Ox-Ce interface area and metallic Cu in the RWGS reaction. Cerium precursor salts enhanced the structural integrity of CeO 2 @Cu and played a vital role in RWGS reaction. These results will support a new direction for exploring micron Cu powder in Cu-based catalysts for CO 2 utilization.
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