Hydrogenation of Citral to Citronellal Catalyzed by Waste Fluid Catalytic Cracking Catalyst Supported Nickel

In this paper, a waste fluid catalytic cracking (FCC) catalyst is used as a carrier to prepare a supported non-noble metal nickel catalyst (Ni/wFCC), which is applied to the selective hydrogenation of citral to citronellal. X-ray powder diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were used to analyze the structural characteristics of the Ni-loaded sample. The catalyst after loading Ni still maintained a good zeolite structure, and the surface impurities were reduced. The effect of reaction conditions on the Ni/wFCC-catalyzed hydrogenation of citral to citronellal was investigated, and the optimal reaction conditions were obtained as follows: a Ni loading of 20 wt %, a catalyst amount of 5.6%, a hydrogenation temperature of 180 °C, a hydrogenation time of 90 min, and a hydrogenation pressure of 3.0 MPa. Under these conditions, the conversion of citral and selectivity of citronellal were 98.5 and 86.6%, respectively, indicating that the Ni/wFCC catalyst had strong catalytic activity and selectivity. This research provided new ideas for the recycling of waste FCC catalysts and industrial synthesis of citronellal.