采用氢等离子体还原法制备了体相过渡金属磷化物Ni2P、MoP、WP和CoP.新鲜制备的金属磷化物在移入固定床反应器之前,用10%Hz孓Hz或0.5%O2—Ar进行钝化,以保护其结构.研究发现,氢等离子体还原法制备的磷化物催化剂的加氢脱硫活性高于程序升温还原(TPR)法制备的催化剂.XRD表征和CO化学吸附结果表明,氢等离子体还原法制备的金属磷化物的粒度较小,活性中心较多.氢等离子体还原法制备的金属磷化物催化剂的高活性可归于其活性中心数量的增加.
The bulk transition-metal phosphides,including Ni2 P, MoP,WP and CoP,were synthesized by means of hydrogen plasma reduction(PR). A mixture of 10% H2S in H2 or 0.5% O2 in Ar was used to passivate the freshly synthesized phosphides to protect their crystal structures before entering fixed bed reactor. Experimental results show that their catalytic performances were higher in the hydrodesulfurization (HDS) than those prepared by the conventional temperature-programmed reduction (TPR) method. XRD characterization and CO chemisorption results reveal that there exist more active sites in the PR-synthesized phosphides than in the TPR-synthesized ones due to the decreased particle sizes of the PR-synthesized metal phosphides. The higher performance of PR- synthesized metal phosphides can be attributed to the increased active sites.