Abstract The effect of zeolite beta particle size on the HDS, HDN, and HDA activities of LCO hydrotreating was investigated on Mo-Ni and W-Ni supported on nano- and micro-sized zeolite beta hydrotreating catalysts. The catalysts were characterized by XRD, BET, TEM, and XPS, and evaluated with an autoclave using real LCO as feed. It was concluded that, with the Mo-Ni catalysts, the catalyst …