Amino-Modified Halloysite Nanotube-Supported Nickel Catalysts for Efficient Reductive Amination of Biomass Aldehydes and Ketones

Abstract

The reductive amination of biomass aldehydes and ketones to synthesize primary amines is a highly promising strategy for biomass value-added. In this study, non-precious metal Ni was loaded onto halloysite nanotubes (HNT) modified by gamma aminopropyltriethoxysilane (APTES) using impregnation chemical reduction method, a series of efficient nickel-based catalysts (denoted as Ni-WHNT) with different Ni loadings were prepared. The compositions and structures of the prepared catalysts were characterized by XPS, TEM, SEM, and so on. The Ni-WHNT catalyst with 10 wt.% Ni could efficiently synthesize furfurylamine (FAM) in the reductive amination of biomass furfural (FAL), and displayed a FAM yield of 99% under mild conditions (90 ℃, 0.5 MPa H2, and 0.3 MPa NH3). Also, the catalyst exhibited a broad scope of various other aldehydes and ketones substrates, and could be recycled up to 5 times without a significant loss in activity. Additionally, the catalytic mechanism, and structure-activity relationship were investigated.