油溶性含Fe、Co或Ni过渡金属催化剂对上湾煤直接液化行为影响OA北大核心

Catalysts play a crucial role in enhancing hydrogen transfer efficiency and overall liquefaction performance.In this study,oil-soluble catalysts iron benzoate(BZ-Fe),nickel benzoate(BZ-Ni)and cobalt benzoate(BZ-Co)were synthesized,and their effects on direct coal liquefaction behavior were investigated.The results indicated that,compared to non-catalytic liquefaction,coal conversion was increased by 2.85％,8.06％and 8.15％,while the oil yield was improved by 7.10％,10.41％and 11.76％under the action of the oil-soluble catalysts,respectively.The catalytic active phases of BZ-Fe,BZ-Ni and BZ-Co were identified as Fe1-xS,Co9S8 and Ni17S18,respectively,and active phases morphological structures showed significant differences.Different valence metal ions(Fe2+/3+、Co+/2+、Ni+/2+/3+)and sulfide ions were distributed across the surfaces of the active phases.The presence of unstable sulfide ions(USIs),thiol groups(-SH)and crystal defects from sulfur vacancies on the surface were closely associated with the hydrogen activation.Additionally,cyclic transformations of USIs and sulfur vacancies occurred on the surfaces of the catalytic active phases,continuously generating hydrogen radicals through the adsorption and dissociation of H2S,thereby supplying active hydrogen for the liquefaction reaction.This study clarifies catalyst hydrogen transfer mechanism from the perspective of active phase,providing a theoretical basis for the development of highly active oil-soluble catalysts.