氢等离子体法还原Ni(H_2PO_2)_2制备高活性Ni_2P加氢脱硫催化剂

Preparation of highly active Ni_2P hydrodesulfurization catalysts by reduction of Ni( H_2PO_2)_2with hydrogen plasma

以次磷酸钠和氯化镍为原料,采用氢等离子体还原法(PR)制备了高活性加氢脱硫(HDS)Ni_2P-PR催化剂,以质量分数为0.8%的二苯并噻吩(DBT)/十氢萘溶液为模型化合物,考察了催化剂的加氢脱硫反应性能,并用X射线衍射(XRD)对催化剂晶相进行表征。新制备的催化剂在移入固定床反应器之前用10%H2S/Ar钝化,以保护其结构不被破坏。实验证明,PR还原法制备的Ni_2P-PR催化剂的加氢脱硫活性高于程序升温还原(TPR)法制备的Ni_2P-TPR催化剂。XRD表征结果表明,Ni_2P-PR的粒度较小,活性中心较多,导致其高活性增加。在Ni_2P-PR催化剂上,DBT主要通过直接脱硫(DDS)路径脱硫。

Ni_2P-PR highly active hydrodesulfurization（ HDS） catalyst is prepared by the hydrogen plasma reduction method（ PR）,in which the precursors containing Ni Cl_2 and Na H_2PO_2 are directly converted to the active phosphide phase. The HDS performances of the prepared catalysts are studied using a model fuel containing 0. 8 wt. % of dibenzothiophene in decalin. The morphologies of the catalysts are characterized by XRD. A mixture of 10% H_2 S in Ar is used to passivate the freshly synthesized Ni_2 P to protect their crystal structures before entering fixed bed reactor.Experimental results show that catalytic performances of Ni_2P-PR prepared by the hydrogen plasma reduction（ PR）method are higher for hydrodesulfurization than that of Ni_2P-TPR. XRD characterization results reveal that smaller particle size and more active centers of Ni_2P-PR catalyst is contributed to its improved catalytic performance. Over the Ni_2P-PR catalyst,DBT is mainly removed though DDS desulfurization.