低温合成Ni2P催化剂及加氢脱硫性能

Low temperature synthesis of Ni2P and its hydrodesulfurization performance

以低价态的次磷酸盐替代高价态的磷酸氢二铵作磷源,采用氢等离子体还原(PR)法制备了体相Ni2P,将Ni2P催化剂移入固定床反应器,评价前用H2S体积分数10%的H2S/Ar钝化,保护催化剂表面结构免于破坏,反应活性与传统程序升温还原(TPR)法制备的催化剂相比较。实验证明,PR法还原不同前体盐,均可以成功制备Ni2P催化剂。次磷酸盐前体制备的Ni2P催化剂的加氢脱硫活性高于磷酸盐前体制备催化剂的活性,也高于TPR法制备的催化剂。XRD表征结果表明,氢等离子体还原法制备的Ni2P的粒度较小,活性中心较多,其高活性可归于活性中心数量的增加。

The bulk Ni2P catalysts were synthesized by hydrogen plasma reduction(PR) method using low-valent hypophosphite as phosphorus source instead of high-valent diammonium hydrogen phosphate. A mixture of 10% H2S in Ar was used to passivate the freshly synthesized Ni2P to protect their crystal structures before they was transferred to a fixed-bed reactor for activity evaluation.The activity of catalysts is compared with the catalyst prepared by the traditional temperature programmed reduction(TPR).Experimental results show that Ni2P can be synthesized by PR from different precursor salts, and the Ni2P synthesized from hypophosphite precursor by PR exhibited higher hydrodesulfurization activity than the Ni2P synthesized from phosphate precursor by PR and the Ni2P prepared by traditional temperature programmed reduction(TPR). XRD characterization results reveal that PR-synthesized Ni2P has more active sites than the TPR-synthesized Ni2P due to the decrease of particle sizes, which results a higher catalytic activity.