Synergistic aluminum dual-atom sites and nickel nanoclusters for acetylene selective hydrogenation.

Abstract

Synergistic catalysis, where distinct active species collaboratively activate different substrates, provides a powerful strategy for achieving chemical transformations with enhanced efficiency. Although Al₂O₃ and bulk aluminum species are widely employed as catalyst supports, they are seldom regarded as active centers, especially in hydrogenation. Here, we show that atomically dispersed Al species can catalyze acetylene conversion at elevated temperatures. Building on this insight, we have designed a synergistic catalyst featuring precisely controlled Al dual-atom sites paired with Ni nanoclusters, synthesized via a solid-transformation-coupled gas-adsorption strategy to overcome the typical activity-selectivity trade-off. Under mild, cost-effective conditions, this catalyst achieves nearly full acetylene conversion with ~90% ethylene selectivity and excellent long-term stability. In situ spectroscopy and theoretical calculations reveal a cooperative mechanism: Ni nanoclusters efficiently dissociate H₂ into active hydrogen species (H*), while adjacent Al dual-atom sites shuttle the H* species to π-adsorbed acetylene, lowering the energy barrier for ethylene formation compared to over-hydrogenation and coke formation.