Promoting effect of Ru on Ni/Mg(Al)O catalysts in DSS-like operation of CH4 steam reforming
Promoting effect of Ru on Ni/Mg(Al)O catalysts in DSS-like operation of CH4 steam reforming
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DOI：
10.1016/j.catcom.2006.07.018
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发表时间：
2007-03
影响因子：
3.7
通讯作者：
Takéshi Miyata;Masato Shiraga;Dalin Li;Ikuo Atake;T. Shishido;Y. Oumi;T. Sano;K. Takehira
中科院分区：
文献类型：
--
作者：
Takéshi Miyata;Masato Shiraga;Dalin Li;Ikuo Atake;T. Shishido;Y. Oumi;T. Sano;K. Takehira
在CH4蒸汽重整的日常启停（DSS）操作中，研究了Ru添加对Ni/Mg(Al)O催化剂活性和可持续性的影响。采用共沉淀法制备Mg2.5(Ni0.5) -Al水滑石，煅烧生成Mg2.5(Al,Ni0.5)O方长石。将方解石粉末浸泡在硝酸钌（III）水溶液中，水滑石在Mg2.5(Al,Ni0.5)O颗粒表面重构，煅烧后形成高度分散的Ru/Ni双金属负载催化剂，并进行还原。钌的加入降低了Ni的还原温度，增加了Ni在催化剂上的吸氢量。同时还提出了Ru - Ni合金的形成或Ru与Ni之间的强相互作用。当Ru-Ni0.5 /Mg2.5(Al)O催化剂在蒸汽净化下进行类似dss操作时，氢气溢出有效地抑制了Ni金属被蒸汽氧化的失活。此外，在类似dss的操作过程中，仅0.05wt%的Ru负载就足以有效抑制失活。
Effects of Ru addition on the activity and the sustainability of Ni/Mg(Al)O catalysts were investigated in the daily start-up and shut-down (DSS) operation of the steam reforming of CH4. Mg2.5(Ni0.5)–Al hydrotalcite was prepared by coprecipitation and calcined to form Mg2.5(Al,Ni0.5)O periclase. When the powders of the periclase were dipped in an aqueous solution of Ru(III) nitrate, the hydrotalcite was reconstituted on the surface of Mg2.5(Al,Ni0.5)O particles, resulting in the formation of highly dispersed Ru/Ni bimetal supported catalysts after the calcination, followed by the reduction. The addition of Ru on Ni caused a decrease in the reduction temperature of Ni and an increase in the amount of H2uptake on the Ni over the catalyst. Formation of Ru–Ni alloy or strong interaction between Ru and Ni was also suggested. When Ru–Ni0.5/Mg2.5(Al)O catalysts were tested in the DSS-like operation under steam purging, the deactivation due to the oxidation of Ni metal by steam was effectively suppressed by hydrogen spillover. Moreover, only 0.05wt% of Ru loading was enough to effectively suppress the deactivation during the DSS-like operation.