CAJ | 학술논문

将醋酸铜热解制备的 Cu2 O/AC (活性炭)催化剂,在氧化( O2/N2)和还原( H2/N2、CO/N2)气氛下进行预处理。350℃下预处理4 h,氧化气氛中Cu2 O完全被氧化为CuO,还原气氛中Cu2 O被还原为单质铜。经CO/N2预处理的催化剂表面Cu0分散性好,催化活性显著升高。在常压固定床微型反应装置上测试,在140℃的反应温度下,碳酸二甲酯的时空收率和选择性分别达到了261.9 mg/(g·h)和74.7%。反应后,还原气氛(H2/N2、CO/N2)预处理的催化剂与Cu2O/AC催化剂中铜物种价态组成趋于一致,催化活性亦趋于一致。关联反应前后催化剂表面铜物种的变化和催化活性的差异,可以认为Cu0具有较高的初始催化活性,Cu2 O活性和价态均较为稳定,CuO活性较低。
장작산동열해제비적 Cu2 O/AC (활성탄)최화제,재양화( O2/N2)화환원( H2/N2、CO/N2)기분하진행예처리。350℃하예처리4 h,양화기분중Cu2 O완전피양화위CuO,환원기분중Cu2 O피환원위단질동。경CO/N2예처리적최화제표면Cu0분산성호,최화활성현저승고。재상압고정상미형반응장치상측시,재140℃적반응온도하,탄산이갑지적시공수솔화선택성분별체도료261.9 mg/(g·h)화74.7%。반응후,환원기분(H2/N2、CO/N2)예처리적최화제여Cu2O/AC최화제중동물충개태조성추우일치,최화활성역추우일치。관련반응전후최화제표면동물충적변화화최화활성적차이,가이인위Cu0구유교고적초시최화활성,Cu2 O활성화개태균교위은정,CuO활성교저。
The Cu2 O/AC catalyst prepared by pyrolysis of copper acetate supported on activatede carbon was pretreated under oxidative ( O2/N2 ) or reductive ( H2/N2 and CO/N2 ) atmospheres. The oxidation/reduction of Cu2 O was completed through pretreatment at 350℃ for 4 h, the Cu2 O in catalyst could be completely oxidized to CuO by oxidative atmosphere, or reduced to metallic copper by reductive atmosphere. The catalyst activities were evaluated in a continuous fixed-bed tubular micro reactor under atmospheric pressure at 140℃. The catalyst pretreated by CO/N2 had good Cu0 dispersion on its surface and exhibited the highest activity. The space-time yield and selectivity of DMC reached 261. 9 mg/( g·h) and 74. 7%, respectively. After 58 h reaction, the valence state of copper species and the catalytic activity of catalysts pretreated by reductive atmosphere were found to be close to that of the Cu2 O/AC catalyst. Comparing the catalytic performance, the characterization of surface and bulk copper species before and after reaction, it was obvious that metallic copper exhibited a high initial activity, while Cu2 O was stable in catalytic activity and valence state, and CuO was low in activity.