Synthesis of Ni2P/Al2O3 utilizing triphenylphosphine (TPP) as the phosphorus source for hydrodeoxygenation of benzofuran

Abstract

A novel route to synthesize highly active Ni₂P/Al₂O₃ (TPP) utilizing triphenylphosphine (TPP) as the phosphorus source at a low temperature of 573 K is described. The as-prepared catalysts were characterized by X-ray diffraction (XRD), CO uptake, Brunner–Emmett–Teller (BET) measurements, and X-ray photoelectron spectroscopy (XPS). The catalytic activity of the Ni₂P/Al₂O₃ (TPP) catalyst and the role of the TPP phosphorus source were studied using hydrodeoxygenation (HDO) of benzofuran (BF) as a probe reaction. The results show that the use of TPP as the phosphorus source could suppress the strong interaction between phosphate and Al₂O₃, thereby the formation of AlPO₄ was avoided. As compared to the Ni₂P/Al₂O₃ prepared by using (NH₄)₂HPO₄ as the phosphorus source, Ni₂P/Al₂O₃ (TPP) possessed significantly higher surface area and smaller Ni₂P particle size. The HDO activity and yield of O-free products over the Ni₂P/Al₂O₃ (TPP) catalyst were increased by 17.2% and 36.0%, respectively, when compared with those found for Ni₂P/Al₂O₃ prepared using (NH₄)₂HPO₄. The use of TPP as the phosphorus source could effectively promote the dehydration of 2-ethylphenol (2-EtPh) to form ethylbenzene (EB), and the demethylation of ethylcyclohexane (ECH) to methylcyclohexane (MCH).