Identification of Ni3Fe alloy as a candidate catalyst for quinoline selective hydrogenation with computations†

The 1,2,3,4-tetrahydroquinoline (py-THQL) is a crucial intermediate and fragment in chemical synthesis, but its production from quinoline (QL) selective hydrogenation in heterogeneous catalysis mainly relies on noble-metal-based catalysts. Therefore, the design of catalysts composed of earth-abundant elements for this reaction is meaningful. In this work, using density functional theory (DFT) calculations, we found the binding energy of QL to be a suitable descriptor to illustrate the general activity trend of metallic catalysts for QL hydrogenation. Among the screened bimetallic alloys composed of Fe, Co, Ni, and Cu, we computationally identified Ni₃Fe as a promising candidate catalyst with high stability, while our systematic mechanistic calculations showed the low energy barriers for each hydrogenation step. Our established DFT-based mean-field microkinetic model indicates a much higher turnover frequency for py-THQL production on the Ni₃Fe(111) surface than on the experimentally reported high-performance AuPd₃(111) surface. This work not only identified a valuable descriptor for the rational catalyst screening for the complex QL hydrogenation reaction but also theoretically predicted a cost-effective Ni₃Fe catalyst for the hydrogenation reaction.