Controlled Synthesis of Nanoporous Nickel Intermetallic Heterostructure Catalyst for Efficient 1,4-Butynediol Hydrogenation

The sustainable hydrogenation of 1,4-butynediol (BYD) to high-purity 1,4-butanediol (BDO) - a cornerstone monomer for biodegradable plastics - remains a critical challenge, demanding catalysts that simultaneously achieve near-quantitative selectivity, energy efficiency, and structural robustness. Here, we report a Mo-doped nanoporous Ni/NiAl 3 heterojunction catalyst (NP-Ni/NiAl 3 -Mo 0.3 ) synthesized via a controlled chemical etching strategy, which overcomes the limitations of conventional core-shell architectures. Unlike traditional NiAl 3 @NP-Ni systems prone to phase segregation, Mo doping stabilizes the NiAl 3 intermetallic matrix while engineering a hierarchically porous heterostructure. The optimized catalyst demonstrates 100% BYD conversion and 99.9% BDO selectivity under mild conditions (30 °C, 2 MPa H 2 ), achieving 38-80% higher conversion rate and 10-20% enhanced selectivity versus NiAl 3 @NP-Ni, Raney Ni and Raney Ni-Mo benchmarks. Remarkably, it exhibits a 30% reduction in apparent activation energy (13.9 kJ·mol -1 ) compared to commercial Raney Ni-Mo and maintains excellent catalytic performance over a wide H 2 pressure range (2-6 MPa), reflecting a significant advance in hydrogen utilization efficiency. Mechanistic studies (H 2 -TPD, in situ DRIFTS, DFT) unveil a synergistic mechanism. The NiAl 3 framework enhances H 2 adsorption capacity, while Mo sites lock the key intermediate (1,4-butenediol, BED) in an optimal adsorption geometry that kinetically suppresses isomerization byproducts. Furthermore, the robust NP-Ni/NiAl 3 -Mo 0.3 structure mitigates Al leaching, retaining 80% BDO selectivity after 8 cycles, significantly outperforming commercial Raney Ni-Mo catalysts. This study introduces an innovative approach to the design of porous intermetallic compound catalysts, establishing a benchmark for the development of catalysts capable of functioning with enhanced efficiency under mild reaction conditions. • Controlled dealloying kinetics yield Mo-doped porous Ni/NiAl 3 heterostructure catalyst. • Synergistic Ni/NiAl 3 -Mo sites enable dual H 2 activation and BED intermediate conversion. • Mo-Ni/NiAl 3 heterostructure enables 100% BYD conversion with 99.9% BDO selectivity at mild condition. • 8-cycle stability with >80% selectivity by intermetallic framework inhibiting Al/Mo leaching.