Unveiling the Ni-Fe coordination environments for enhanced 1,4-butanediol selectivity in 1,4-butynediol hydrogenation

Biodegradable materials such as PBAT and PBS offer a promising solution to plastic pollution, which require 1,4-butanediol (BDO) as a key monomer, predominantly produced via 1,4-butynediol (BYD) hydrogenation. In this study, we present an innovative approach for achieving enhanced BDO selectivity by regulating the Ni-Fe coordination environments in bimetallic catalysts for hydrogenation. The novel Fe/Ni-SiO₂ catalyst features framework-embedded Ni species and surface-anchored Fe sites and shows a fantastic complementary interaction between Ni-FeO_x synergy sites; namely, Ni sites efficiently dissociate H₂ to enable successive hydrogenation, while the coordinatively unsaturated FeO_x species can preferentially stabilize the terminal-OH groups in both BYD and BED intermediates during adsorption while suppressing other side reactions. Furthermore, the Fe/Ni-SiO₂ catalyst, characterized by the lowest concentration of medium-strength acid sites and the largest O vacancies, showed minimal formation of isomerization byproducts, thereby achieving the highest BDO selectivity of 94.1% at 50 °C and 1 MPa H₂. These results thus provide valuable guidance for designing bimetallic catalysts for efficient selective hydrogenation.