Catalytic performance tests and deactivation behavior of Ni-W/Al2O3 catalysts developed for upgrading coal-derived liquids Original Research Article

A Nisingle bondW catalyst designed and developed for upgrading coal-derived liquids was used in 500 and 1000 h catalyst performance tests using coal-derived kerosene and gas oil, respectively. The catalyst showed considerable improvement in hydrodenitrogenation (HDN) and hydrogenation (HY) activities and less initial deactivation as compared to commercial catalysts. The catalysts used for the catalyst performance tests were characterized to clarify catalyst deactivation behavior. Precise characterization of the used catalysts by means of X-ray photoelectron spectroscopy, X-ray absorption fine structure (EXAFS and XANES), and transmission electron microscopy revealed that crystal growth of WS2-like structures and changes in the sulfided states and in the local structure of tungsten on the catalysts occurred during the upgrading reaction. These findings gave new insights for improving catalytic activity and the life of the newly developed catalyst.