Zeolite‐Encaged Pd–Mn Nanocatalysts for CO<sub>2</sub> Hydrogenation and Formic Acid Dehydrogenation
Qiming Sun, Benjamin W. J. Chen, Ning Wang, Qian He, Albert M. Chang, Chia‐Min Yang, Hiroyuki Asakura, Tsunehiro Tanaka, Max J. Hülsey, Chi‐Hwa Wang, Jihong Yu, Ning Yan
Abstract
Abstract A CO 2 ‐mediated hydrogen storage energy cycle is a promising way to implement a hydrogen economy, but the exploration of efficient catalysts to achieve this process remains challenging. Herein, sub‐nanometer Pd–Mn clusters were encaged within silicalite‐1 (S‐1) zeolites by a ligand‐protected method under direct hydrothermal conditions. The obtained zeolite‐encaged metallic nanocatalysts exhibited extraordinary catalytic activity and durability in both CO 2 hydrogenation into formate and formic acid (FA) dehydrogenation back to CO 2 and hydrogen. Thanks to the formation of ultrasmall metal clusters and the synergic effect of bimetallic components, the PdMn 0.6 @S‐1 catalyst afforded a formate generation rate of 2151 mol formate mol Pd −1 h −1 at 353 K, and an initial turnover frequency of 6860 mol mol Pd −1 h −1 for CO‐free FA decomposition at 333 K without any additive. Both values represent the top levels among state‐of‐the‐art heterogeneous catalysts under similar conditions. This work demonstrates that zeolite‐encaged metallic catalysts hold great promise to realize CO 2 ‐mediated hydrogen energy cycles in the future that feature fast charge and release kinetics.