铝源对Ni/Al2O3催化剂结构及其CO2-CH4重整性能的影响  

Effect of aluminum source on the structure and performance of Ni/Al2O3 catalysts in CO2-CH4 reforming

作　　者：何小强 莫文龙[1] 覃松 马凤云[1] HE Xiao-qiang;MO Wen-long;QIN Song;MA Feng-yun(Key Laboratory of Coal Clean Conversion&Chemical Engineering Process(Xinjiang Uyghur Autonomous Region),College of Chemistry and Chemical Engineering,Xinjiang University,Urumqi 830046,China)

机构地区：[1]新疆大学化学化工学院,煤炭清洁转化与化工过程新疆维吾尔自治区重点实验室,新疆乌鲁木齐830046

出　　处：《燃料化学学报》2020年第2期221-230,I0007,共11页Journal of Fuel Chemistry and Technology

基　　金：新疆维吾尔自治区自然科学基金(2018D01C034)资助。

摘　　要：以三种不同铝源采用溶液燃烧法制备了系列Ni/Al2O3催化剂,通过XRD、H2-TPR、NH3-TPD、N2吸附-脱附、TGDTG和TPH等分析方法对反应前后催化剂进行了表征,研究了铝源对Ni/Al2O3催化剂结构、表面性质及其CO2-CH4重整性能的影响。结果表明,以Al(NO3)3·9H2O为铝源制备的NiNO-AlNO催化剂比表面积较大,达102 m2/g;高温还原峰面积大,峰型更为弥散;且载体Al2O3具有一定的结晶性。而以Al2(SO4)3·18H2O和AlCl3·6H2O为铝源制备的NiNO-AlSO和NiNO-AlCl催化剂,其载体以无定型Al2O3存在,活性组分Ni晶粒粒径大、分散性差,还原峰面积较小,与载体的相互作用较弱。其中,由于硫酸铝较为稳定,需要在更高温度下才能转化为Al2O3,且所制备NiNO-AlSO催化剂中残留有含硫物质,使得其表面酸性较强。评价结果显示,NiNO-AlNO催化剂活性较高,稳定性好,CH4转化率为31.21%,CO2转化率为48.97%。积炭分析结果发现,NiNO-AlNO催化剂表面积炭量最少,沉积炭主要以无定型态存在,具有良好的抗积炭性能。Three Ni/Al2O3 catalysts were prepared with different aluminum sources by the solution combustion method and characterized by XRD,H2-TPR,NH3-TPD,N2 sorption,TG-DTG and TPH. The effect of aluminum source on the structure and performance of Ni/Al2O3 catalysts in CO2-CH4 reforming was then investigated. The results show that the NiNO-AlNO catalyst with Al(NO3)3·9H2O as aluminum source owns a large surface area of 102 m2/g and a wide and intense high-temperature reduction peak;besides,the Al2O3 support displays certain crystallinity. In contrast,the NiNO-AlSO and NiNO-AlCl catalysts,prepared with Al2(SO4)3·18 H2O and AlCl3·6 H2O sources,respectively,are composed of amorphous Al2O3 as support and crystal Ni as active component;the Ni species is poorly dispersed and present as large grains,with a small reduction peak and weak interaction with the support. In particular,because of the high stability of Al2(SO4)3 and difficulty in converting Al2(SO4)3 to active Al2O3 at high temperature,certain sulfur-containing substances are preserved and the resultant NiNO-AlSO catalyst shows strong surface acidity. The catalytic evaluation results indicate that the NiNO-AlNO catalyst exhibits high activity and stability in the CO2-CH4 reforming;the conversions of CH4 and CO2 are 31.21% and 48.97%,respectively. The carbon deposition analysis illustrates that the content of deposited carbon( present mainly in the amorphous form) on the NiNO-AlNO catalyst is rather low,suggesting a high resistance against carbon deposition.

关 键 词：NI/AL2O3催化剂 CO2-CH4重整 铝源 积炭 

分 类 号：O643.32[理学—物理化学]