Hollow ZIF-67-derived Co@N-doped carbon nanotubes boosting the hydrogenation of phenolic compounds to alcohols

The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability, environmental friendliness, and non-toxicity is of great importance. Herein, a series of Co-based catalysts, named Co@NCNTs, were designed and constructed by direct pyrolysis of hollow ZIF-67 (HZIF-67) under H₂/Ar atmosphere. The evolution of the catalyst surface from the shell layer assembled by ZIF-67-derived particles to the in situ-grown hollow nitrogen-doped carbon nanotubes (NCNTs) with certain length and density is achieved by adjusting the pyrolysis atmosphere and temperature. Due to the synergistic effects of in situ-formed hollow NCNTs, well-dispersed Co nanoparticles, and intact carbon matrix, the as-prepared Co@NCNTs-0.10-450 catalyst exhibits superior catalytic performance in the hydrogenation of phenolic compounds to alcohols. The turnover frequency value of Co@NCNTs-0.10-450 is 3.52 h⁻¹, 5.9 times higher than that of Co@NCNTs-0.40-450 and 4.5 times higher than that of Co@NCNTs-0.10-550, exceeding most previously reported non-noble metal catalysts. Our findings provide new insights into the development of non-precious metal, efficient, and cost-effective metal–organic framework-derived catalysts for the hydrogenation of phenolic compounds to alcohols.