Co(x)/ZRP催化剂的CH_(4)-SCR脱硝性能研究

CH_(4)-SCR performance of Co(x)/ZRP Catalysts

为消除氮氧化物对人类健康和生态环境的危害,以甲烷为还原剂进行选择性催化脱硝(CH_(4)-SCR)得到了普遍的关注。研发高活性的CH_(4)-SCR脱硝催化剂成为该技术的研究重点。采用浸渍法制备了Co(x)/ZRP催化剂,考察了钴负载量对Co(x)/ZRP催化剂CH_(4)-SCR脱硝性能的影响。利用X射线衍射仪(XRD)、H_(2)程序升温还原(H_(2)-TPR)、吡啶吸附红外光谱(Py-IR)、NH_(3)程序升温脱附(NH_(3)-TPD)和NO程序升温脱附(NO-TPD)等对Co(x)/ZRP催化剂的理化性质进行了表征,在常压固定床微型反应器上评价了Co(x)/ZRP催化剂的CH_(4)-SCR脱硝性能。结果表明:Co(x)/ZRP催化剂中钴物种为Co_(3)O_(4),钴负载量增加,Co_(3)O_(4)晶粒变大,催化剂的氧化还原能力和NO的吸脱附性能均得到改善。随着钴负载量的增加,Co(x)/ZRP催化剂的CH_(4)-SCR脱硝活性先增强后降低,与催化剂中的中强酸量在总酸中的变化规律基本一致。其中Co(20)/ZRP催化剂的中强酸量较多,CH_(4)-SCR脱硝性能较好,T_(m)为342℃,X_(No)^(max)为39.2%。催化剂表面的L酸位以及中强酸量对催化剂的CH_(4)-SCR催化脱硝活性具有重要作用。

To eliminate the harm of nitrogen oxides to human health and ecological environment,selective catalytic denitrification using methane as a reducing agent(CH_(4)-SCR)has received widespread attention.Developing highly active CH_(4)-SCR denitrification catalysts has become a research focus of this technology.In this article,Co(x)/ZRP catalysts were prepared by impregnation method,and the effects of Co(x)/ZRP catalysts with different cobalt loading amounts on the denitrification performance of CH_(4)-SCR were investigated.The physicochemical properties of Co(x)/ZRP catalysts were characterized using XRD,H_(2)-TPR,Py-IR,NH_(3)-TPD and NO-TPD methods.The CH_(4)-SCR denitrification performance of Co(x)/ZRP catalysts was evaluated on fixed bed micro-reactor under atmospheric pressure.The results showed that the cobalt species in the Co(x)/ZRP catalyst were Co_(3)O_(4).With the increase of cobalt loading,the Co_(3)O_(4)grains became larger,the redox ability and NO adsorption and desorption performance of the catalyst were improved.With the increase of cobalt loading,the denitrification activity of Co(x)/ZRP catalyst first increased and then decreased,which was consistent with the variation of medium strong acid amount in the total acid of the catalyst.Among them,the Co(20)/ZRP catalyst had a higher amount of medium strong acid,and the CH_(4)-SCR denitrification performance was good,with T_(m)of 342℃,X_(No)^(max)of 39.2%.The L-acid and medium strong acid content of the catalyst played an important role in the CH_(4)-SCR catalytic denitrification activity of the catalyst.