Innovative Carbon‐Al2O3 Composite Supports for Catalysts in CO2‐to‐Methanol Hydrogenation

Abstract The increase in CO 2 emissions contributes massively to the aggravation of climate change. The hydrogenation of CO 2 to methanol is a possible approach for reducing this gas emissions by converting emitted CO 2 into a value‐added product. Therefore, the development of efficient catalysts for this reaction is fundamental. In this study, CuZn bimetallic catalysts supported on composites of AC‐Al 2 O 3 and CNT‐Al 2 O 3 were synthesized, and their catalytic performance was assessed. The catalytic experiments were conducted at 250 °C and 30 bar for 15 h, under a H 2 :CO 2 ratio of 3. The catalysts CuZn/AC‐Al 2 O 3 (50:50) and CuZn/AC‐Al 2 O 3 (70:30) demonstrated an overall improved catalytic performance when compared to the catalyst supported on pristine AC, indicating that the increased presence of mesopores and the synergistic effect between AC and Al 2 O 3 are beneficial. The catalyst CuZn/CNT‐Al 2 O 3 (90:10) performed similarly to the catalyst supported on pristine CNT. CuZn/CNT‐Al 2 O 3 (50:50) and CuZn/CNT‐Al 2 O 3 (70:30) displayed reduced CO 2 conversion but enhanced methanol selectivity compared to the reference catalyst, CuZn/Al 2 O 3 , suggesting that the presence of CNT is advantageous for methanol selectivity. The catalyst CuZn/CNT presented the highest methanol yield, and was stable for over 80 h on a TOS experiment.