“…Besides, 35 S radioactive tracer methods were developed to determine the sulfidation process of HDS catalysts as well as to describe the HDS reaction mechanism over various catalysts under real working conditions [32,34,35,[73][74][75][76][77][78][79][80]. On the other hand, with the recent developments of the computer simulations, new insights in the state of the HDS catalysts surface [81][82][83][84] as well as an overview of the HDS mechanism over the simulated surfaces were concurrently proposed [85,86].…”