Zn(H_(2)PO_(4))_(2)/AC在气固相乙炔水合反应中的应用

Effect of zinc dihydrogen phosphate on gas-solid acetylene hydration

为了探究Zn(H_(2)PO_(4))_(2)对气固相乙炔水合反应的性能影响,利用过体积浸渍法制备了Zn/AC、Zn(H_(2)PO_(4))_(2)/AC催化剂。在240℃,GHSV((C_(2)H_(2)))=90 h^(-1),n((H_(2)O))/n((C_(2)H_(2)))=4的反应条件下,于固定床反应器中测试了催化剂的催化性能。性能测试结果表明Zn(H_(2)PO_(4))_(2)/AC催化剂活性较好,在反应10 h后,乙炔的转化率保持在93%左右,乙醛的选择性在70%左右。表征结果证明,Zn(H_(2)PO_(4))_(2)/AC催化剂中Zn得到了电子,电子云密度增大,这对反应是有利的。酸位点含量和总酸的含量增加,促进了Zn^(2+)和Bronsted酸位点结合,(ZnOH)^(+)活性物种含量增多,同时积碳量减少,进而提高了催化活性。本研究将为后续乙炔水合无汞催化剂的研究提供一种新的研究思路。

To investigate the effect of Zn(H_(2)PO_(4))_(2)on the performance of gas-solid phase acetylene hydration reaction,Zn/AC,and Zn(H_(2)PO_(4))_(2)/AC-E catalysts were prepared using the over-volume impregnation method.The catalytic performance of the catalysts was tested in a fixed-bed reactor at 240℃,GHSV(C_(2)H_(2))=90 h^(-1)and n(H_(2)O)/n(C2 H_(2))=4 reaction conditions.The performance test results showed that the Zn(H_(2)PO_(4))_(2)/AC catalyst was more active,and the conversion of acetylene was maintained at about 93%and the selectivity of acetaldehyde at about 70%after 10 h of reaction.The characterization results proved that Zn in the Zn(H_(2)PO_(4))_(2)/AC catalyst gained electrons,and the electron cloud density increased,which was favorable for the reaction.The increase in acid site content and total acid content promoted the binding of Zn^(2+)and Bronsted acid sites,and the content of(ZnOH)^(+)active species increased while the amount of carbon accumulation decreased,which in turn improved the catalytic activity.This study will provide a new research idea for the subsequent study of acetylene hydration mercury-free catalysts.