Dual Scale Hydrogen Transfer Bridge Construction for Biomass Tandem Reductive Amination

Abstract

Hydrogen spillover has provided great insights for elevating catalytic performance in hydrogen-involved heterogeneous catalytic processes, which is normally promoted by the reducible oxide support. However, it seems powerless in some cases when the unreducible oxide is desired to play the role in activating another molecular reactant, and thus the competition needs to be reconciled. Herein, taking tandem reductive amination of furfural as an example, we constructed the Ru/Ga2O3/MgAlGaO x catalyst, in which the metallic Ru sites and Al3+ sites take responsibility for H2 dissociation and intermediate Schiff base activation, respectively. More attractively, nanosized Ga2O3 and atomic distributed Ga3+ in MgAlGaO x can be considered as dual scale hydrogen transfer bridges to break the deadlock. As the dissociated H* efficient spillover to Al3+ site is timely, facilitating the vital step of hydrogenolysis intermediate to furfurylamine, the as-synthesized catalysts thus achieved satisfactory catalytic performance, universality, and cycling stability (93% yield, 80.43 gFAM·gRu –1·h–1 product formation rate, broad scope of 14 substrates, and recycling 5 times) under both mild H2 pressure and extremely low NH3 feeding conditions. Through designed in/ex-situ experiments and DFT calculations, such a promotional effect of dual scale hydrogen transfer was revealed. This work opens a strategy avenue for other hydrogen-involved complex reactions and presents a prospective catalyst for biomass upgrading under mild condition.

Highly Active and Sulfur-Tolerant Ruthenium Phosphide Catalyst for Efficient Reductive Amination of Carbonyl Compounds

“…Primary amines play a pivotal role in the chemical industry, finding widespread applications in the synthesis of pharmaceuticals, agrochemicals, polymers, dyes, and functionalized materials. , Reductive amination of carbonyl compounds with H 2 and NH 3 is one of the most attractive synthetic processes of primary amines due to the widely available and inexpensive feedstocks and high atom efficiency. To date, numerous homogeneous and heterogeneous catalysts have been developed for this reaction. − In the past decade, metal nanoparticle catalysts based on Ru, − Rh, Pd, , Pt Ni, , and Co − were reported. However, supported metal catalysts often require harsh reaction conditions.…”