摘要:
采用共沉淀法制备Cu和Zn取代的六铝酸盐(LaCuxZn1-xAl11O19-δ,x为0,0.2,0.4,0.5,0.6,0.8,1)催化剂,考察了催化剂对N2O的分解活性.结果表明,在1200℃焙烧4 h可以形成完整的六铝酸盐晶型,Cu和Zn能够取代Al3+很好地促进六铝酸盐晶体结构的形成;LaCuxZn1-xAl11O19-δ催化剂对N2O分解有很好的催化活性,其中LaCuxZn1-xAl11O19-δ活性最好.在LaCuxZn1-xAl11O19-δ六铝酸盐中,Cu为N2O催化分解的主要活性元素,Zn有助于提高催化剂的稳定性,但Zn在催化剂中的作用很小.
关键词:
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N2O
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分解
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六铝酸盐
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催化剂
Abstract:
Cu,Zn substituted hexaaluminates(LaCuxZn1-xAl11O19-δ,x=0,0.2,0.4,0.5,0.6,0.8,1)was prepared with co-precipitation method.The structure and physico-chemical properties of the samples were characterized by means of XRD,BET and TPR technique.The activity of N2O decomposition over the prepared samples were measured in a miniature fixed bed reactor.The results showed that the catalyst prepared using(NH42CO3 as precipitant could obtain good hexaaluminate phase under 1200℃ calcinations for 4h.Cu,Zn could be contribute to form the hexaaluminate lattice because of their good synergic.LaCuxZn1-xAl11O19-δ possessed highest catalytic activity in all the samples for N2O decomposition reaction.In the catalyst Cu is the active element for decomposition of N2O and Zn maybe contribute to enhance the stability of the catalyst.However,Zn itself had less effect on catalytic activity for N2O decomposition reaction.