Porous carbon-confined palladium nanoclusters for selective dehydrogenation of formic acid and hexavalent chromium reduction

Formic acid (FA) is a common liquid hydrogen storage carrier with high hydrogen content, easy availability, and relative stability, which has been widely used in portable hydrogen storage devices. Developing an efficient FA dehydrogenation (FAD) and FA reduction of hexavalent chromium (Cr(VI)) heterogeneous catalyst is necessary to improve its slow kinetics, but still a challenge. Herein, uniformly dispersed Pd nanoclusters (NCs) (1.26 nm) anchored by amino functionalized porous carbon (C-NH2) were successfully synthesized via a simple approach. Due to the small size of Pd nanoclusters, abundant active sites, the promotion of amine groups on the surface and the electronic interaction between Pd NCs and carriers, the prepared Pd/C-NH2 catalyst showed excellent catalytic efficiency in additive-free FAD (turnover frequency of 3834 h- 1 at 323 K) and reduction of Cr(VI) (rate constant of 0.12 min- 1 at 298 K), which is better than many reported catalysts. The research provides new ideas for designing efficient catalysts that can be used in various catalytic applications in the environmental and energy fields.