Efficient hydrogen release from dodecahydro-N-ethylcarbazole over ultrafine PdNi bimetallic clusters anchored on hierarchical Beta-NCNT architectures

Dodecahydro-N-ethylcarbazole (12H-NEC) is a promising liquid organic hydrogen carrier; however, its practical application is limited by sluggish dehydrogenation kinetics. Herein, ultrafine PdNi bimetallic nanoclusters were anchored on a composite support comprising Beta zeolite and N-doped carbon nanotubes (Beta-NCNT) through in situ chemical vapor deposition followed by galvanic replacement. The Beta-NCNT architecture enhances interfacial electron transport and promotes strong metal-support interactions (SMSI). These interactions facilitate electron transfer from Pd to Ni, thereby generating electron-deficient Pd sites that optimize reactant adsorption and activation. Consequently, the PdNi 20 /Beta-NCNT catalyst achieves complete 12H-NEC dehydrogenation within 2 h and retains 90% hydrogen-release efficiency after 14 cycles. DFT calculations further indicate that PdNi coupling modifies the adsorption of hydrogenated NEC species and provides more favorable thermodynamic characteristics for the investigated dehydrogenation stages. Therefore, these effects help alleviate the kinetic limitations of 12H-NEC dehydrogenation and provide a basis for the rational design of efficient LOHC catalysts.