燃料化学学报
燃料化學學報
연료화학학보
JOURNAL OF FUEL CHEMISTRY AND TECHNOLOGY
2009年
6期
707-712
,共6页
唐明兴%李学宽%吕占军%葛晖%周立公
唐明興%李學寬%呂佔軍%葛暉%週立公
당명흥%리학관%려점군%갈휘%주립공
加氢脱硫%苯%镍催化剂%氧化锌
加氫脫硫%苯%鎳催化劑%氧化鋅
가경탈류%분%얼최화제%양화자
hydrodesulfurization%Ni/ZnO%benzene
比较了浸渍法与共沉淀法制备的Ni/ZnO催化剂对芳烃原料的深度脱硫活性和选择性,并采用H_2-TPR、XRD和BET等手段对催化剂进行了表征.结果表明,NiO与载体ZnO之间的相互作用程度对催化剂的性能有很大影响.与ZnO相互作用较弱的游离态NiO还原后生成的Ni~0,导致苯加氢生成环己烷;与ZnO相互作用较强的NiO还原后生成的Ni~0具有脱硫能力但不是苯加氢活性中心.共沉淀法制备的催化剂由于NiO与载体相互作用较强,游离态NiO较少,且比表面积相对较大,因而具有较高的活性和选择性.同时发现,还原温度对催化剂的性能具有很大影响,在400℃还原时开始出现Ni_xZn_y合金,且随着还原温度的升高,晶粒长大,比表面积降低,导致催化剂活性降低.Sn助剂的加入能增加NiO与载体的相互作用,抑制游离态的NiO生成,从而减少苯的损失.
比較瞭浸漬法與共沉澱法製備的Ni/ZnO催化劑對芳烴原料的深度脫硫活性和選擇性,併採用H_2-TPR、XRD和BET等手段對催化劑進行瞭錶徵.結果錶明,NiO與載體ZnO之間的相互作用程度對催化劑的性能有很大影響.與ZnO相互作用較弱的遊離態NiO還原後生成的Ni~0,導緻苯加氫生成環己烷;與ZnO相互作用較彊的NiO還原後生成的Ni~0具有脫硫能力但不是苯加氫活性中心.共沉澱法製備的催化劑由于NiO與載體相互作用較彊,遊離態NiO較少,且比錶麵積相對較大,因而具有較高的活性和選擇性.同時髮現,還原溫度對催化劑的性能具有很大影響,在400℃還原時開始齣現Ni_xZn_y閤金,且隨著還原溫度的升高,晶粒長大,比錶麵積降低,導緻催化劑活性降低.Sn助劑的加入能增加NiO與載體的相互作用,抑製遊離態的NiO生成,從而減少苯的損失.
비교료침지법여공침정법제비적Ni/ZnO최화제대방경원료적심도탈류활성화선택성,병채용H_2-TPR、XRD화BET등수단대최화제진행료표정.결과표명,NiO여재체ZnO지간적상호작용정도대최화제적성능유흔대영향.여ZnO상호작용교약적유리태NiO환원후생성적Ni~0,도치분가경생성배기완;여ZnO상호작용교강적NiO환원후생성적Ni~0구유탈류능력단불시분가경활성중심.공침정법제비적최화제유우NiO여재체상호작용교강,유리태NiO교소,차비표면적상대교대,인이구유교고적활성화선택성.동시발현,환원온도대최화제적성능구유흔대영향,재400℃환원시개시출현Ni_xZn_y합금,차수착환원온도적승고,정립장대,비표면적강저,도치최화제활성강저.Sn조제적가입능증가NiO여재체적상호작용,억제유리태적NiO생성,종이감소분적손실.
Ni/ZnO catalyst prepared by impregnation and co-precipitation methods for ultra-deep hydrodesulfurization of benzene was studied. The structures and properties of the catalysts were investigated by H_2-TPR, XRD and BET techniques. It was found that the interaction between NiO and ZnO has important influence on the activity and selectivity of the catalysts. NiO with weak interaction with ZnO has high benzene hydrogenation activity after reduction by H_2, resulting in conversion of benzene to cyclohexane, whereas, NiO with strong interaction with ZnO has hydrodesulfurization activity, but has no benzene hydrogenation activity. The catalysts prepared by impregnation showed certain content of weak-interaction NiO, so the benzene exhibited great lose. The NiO, prepared by co-precipitation, has strong interaction with ZnO,so the catalyst has better selectivity toward desulfurization. Furthermore, the catalyst prepared by co-precipitation had a higher BET area. As a result, the activity and selectivity were higher over catalyst prepared with co-precipitation than that over catalyst prepared by impregnation. It was found that reduction temperature has important influence on catalyst activity and selectivity. Catalyst reduced at 400℃showed the best performance while reduction at 500℃ resulted in the decrease of the activity due to crystal particles sintering and specific surface area decrease. Addition of Sn can change the interaction between NiO and ZnO. Due to the inhibition of formation of weak-interaction NiO, Sn addition suppressed greatly the loss of benzene.
