化工进展
化工進展
화공진전
Chemical Industry and Engineering Progress
2015年
10期
3671-3675
,共5页
苯酚%加氢%镍基催化剂%环己酮%环己醇%还原
苯酚%加氫%鎳基催化劑%環己酮%環己醇%還原
분분%가경%얼기최화제%배기동%배기순%환원
phenol%hydrogenation%nickel supported catalysts%cyclohexanol%cyclohexanone%reduction
通过等体积浸渍法分别将Ni(NO3)2、NiCl2、NiSO43种镍前体浸渍于A12O3或SiO2载体上,然后通过H2高温还原法制备了负载型镍基催化剂,考察了镍前体、载体种类、镍负载量、反应条件等对镍基催化剂苯酚加氢性能的影响。结果表明,对比3种镍前体,在H2高温还原体系中Ni(NO3)2最容易被还原,制备的镍基催化剂苯酚加氢活性最高。SiO2负载的镍基催化剂活性远高于γ-Al2O3催化剂。适宜的 Ni 负载量有助于活性组分的分散和催化活性的提高。镍基催化剂的苯酚加氢产物以环己醇为主,相对缓和的反应条件更容易生成环己酮。在非极性溶剂正庚烷或环己烷存在下,苯酚加氢反应速率远远高于极性溶剂水或乙醇存在下的结果,而且环己酮的选择性更高。
通過等體積浸漬法分彆將Ni(NO3)2、NiCl2、NiSO43種鎳前體浸漬于A12O3或SiO2載體上,然後通過H2高溫還原法製備瞭負載型鎳基催化劑,攷察瞭鎳前體、載體種類、鎳負載量、反應條件等對鎳基催化劑苯酚加氫性能的影響。結果錶明,對比3種鎳前體,在H2高溫還原體繫中Ni(NO3)2最容易被還原,製備的鎳基催化劑苯酚加氫活性最高。SiO2負載的鎳基催化劑活性遠高于γ-Al2O3催化劑。適宜的 Ni 負載量有助于活性組分的分散和催化活性的提高。鎳基催化劑的苯酚加氫產物以環己醇為主,相對緩和的反應條件更容易生成環己酮。在非極性溶劑正庚烷或環己烷存在下,苯酚加氫反應速率遠遠高于極性溶劑水或乙醇存在下的結果,而且環己酮的選擇性更高。
통과등체적침지법분별장Ni(NO3)2、NiCl2、NiSO43충얼전체침지우A12O3혹SiO2재체상,연후통과H2고온환원법제비료부재형얼기최화제,고찰료얼전체、재체충류、얼부재량、반응조건등대얼기최화제분분가경성능적영향。결과표명,대비3충얼전체,재H2고온환원체계중Ni(NO3)2최용역피환원,제비적얼기최화제분분가경활성최고。SiO2부재적얼기최화제활성원고우γ-Al2O3최화제。괄의적 Ni 부재량유조우활성조분적분산화최화활성적제고。얼기최화제적분분가경산물이배기순위주,상대완화적반응조건경용역생성배기동。재비겁성용제정경완혹배기완존재하,분분가경반응속솔원원고우겁성용제수혹을순존재하적결과,이차배기동적선택성경고。
Nickel-based catalysts supported onγ-A12O3 or SiO2 from Ni(NO3)2,NiCl2 or NiSO4 as precursors were prepared with incipient technique and further reduced by H2at high temperature. Influence of nickel precursors,catalyst supports,nickel loadings and reaction conditions on the catalytic performance of phenol hydrogenation was investigated. Among three nickel precursors studied,Ni(NO3)2was the most easily reduced by H2 and the catalyst prepared displayed the best catalytic performance. It was shown that the nickel catalyst on SiO2exhibited higher performance than that onγ-Al2O3. The reasonable nickel loading was helpful to active component dispersion and good catalytic performance. The main product on the nickel supported catalysts was not the cyclohexanone but the cyclohexanol,and yet,the selectivity of cyclohexanone could be increased under the modest reaction conditions. The reaction rate or the cyclohexanone selectivity could be improved in nonpolar solvents like heptane or cyclohexane compared to that in polar solvents,like alcohol or H2O.