A design strategy of high-activity swarm mobile nanocatalysts for hydrogenolysis of complex N-benzyl compounds via anchoring–confinement synergy

Abstract

Ultrasmall metal nanoparticles are used as active sites in numerous heterogeneous catalysts. However, the metal sites in these catalysts are typically considered to be static, which limits the transformation of complex organic molecules with special multidimensional spatial structures that are distant from these sites. This study proposes and verifies a swarm mobile catalyst design strategy based on the synergistic induction of the “anchoring–confinement effect”. Enhanced catalytic efficiency is achieved by increasing the collision frequency between active sites and reactants. Specifically, the ultrasmall Pd(OH)₂ nanoparticles (approximately 1.85 nm), formed under the synergistic effect, are rapidly transformed into mobile Pd species that participate in the reaction. The special support with hierarchical macro–meso–micropores effectively enhances the mass transfer process. The catalyst demonstrates the highest activity in the hydrogenation debenzylation of hexabenzylhexaazaisowurtzitane (HBIW), achieving a high turnover number (TON) of 161.4 and a product yield of 91.4%, with the amount of Pd used in the catalyst being only 0.85 wt‰ of HBIW at near-room temperature. The successful implementation of this strategy offers a new concept for the design and synthesis of efficient heterogeneous catalysts.