Ultrafine PdCo nanoparticles on amine-functionalized CeZrSBA-15 with short channels for efficient H2 production from formic acid dehydrogenation

Abstract

The rational design of heterogeneous catalysts with remarkable activity and low cost is essential yet challenging for formic acid (HCOOH, FA) dehydrogenation. Herein, ultrafine bimetallic PdCo nanoparticles (NPs) dispersed on the amine-functionalized CeZrSBA-15 (CeZrSBA-15-NH2) with short channels have been successfully prepared. The optimized catalyst Pd3Co2/CeZrSBA-15-NH2 (the Pd/Co molar ratio is 3:2) displayed the extraordinary catalytic performance of FA dehydrogenation with 100 % FA conversion and H2 selectivity. Furthermore, in the presence of sodium formate (SF) as an additive, the catalytic system achieved an impressive initial turnover frequency (TOF) of 2001 h−1 at a temperature of 323 K, which is better than the TM (transition metal)-containing Pd-based heterogeneous systems ever published under the similar reaction conditions. The exceptional catalytic activity is ascribed to several key factors, including the presence of short channels that facilitate the efficient transfer of reactants, the ultrafine size (1.6 nm) and uniform dispersion of PdCo nanoparticles, which serve as the active catalytic sites on the CeZrSBA-15-NH2 support. Additionally, the regulated electronic effects induced by Pd and Co, coupled with the metal-support interaction (MSI) effect, further enhance the catalytic performance. This work affords a new paradigm into developing effective mesoporous silica-based heterogeneous catalysts for H2 production from FA dehydrogenation.