CAJ | 학술논문

采用沉淀法制备了Co3 O4催化剂,并将催化剂在流动的N2或O2气氛中于不同温度下进行预处理。通过X射线衍射( XRD)、热重-差示扫描量热分析( TG-DSC)、程序升温脱附( O2/CO2-TPD, HCHO-TPSR)和原位漫反射傅里叶变换红外光谱( in situ DRIFTS)等手段对催化剂表面物种进行了表征。结果表明, Co3 O4-N2-200催化剂表面存在Co3+不饱和配位中心和丰富的弱配位氧负离子,容易形成双配位的甲酸盐,并转化成单配位的甲酸盐,进一步分解为产物。
채용침정법제비료Co3 O4최화제,병장최화제재류동적N2혹O2기분중우불동온도하진행예처리。통과X사선연사( XRD)、열중-차시소묘량열분석( TG-DSC)、정서승온탈부( O2/CO2-TPD, HCHO-TPSR)화원위만반사부리협변환홍외광보( in situ DRIFTS)등수단대최화제표면물충진행료표정。결과표명, Co3 O4-N2-200최화제표면존재Co3+불포화배위중심화봉부적약배위양부리자,용역형성쌍배위적갑산염,병전화성단배위적갑산염,진일보분해위산물。
The Co3 O4 catalysts were prepared via precipitation methods, and then were pretreated in N2 or O2 at different temperatures. Based on the study of formaldehyde catalytic oxidation, the catalytic performances were investigated with the detailed surface characterization via temperature programmed desorption ( O2/CO2-TPD, HCHO-TPSR) , thermogravimetric-differential scanning calorimetry( TG-DSC) and in situ diffuse reflec-tance infrared fourier transform spectroscopy ( in situ DRIFTS ) . The results presented that Co3 O4-N2-200 showed the optimal catalytic performance, because there were rich unsaturated coordination centers of Co3+and negative oxygen ions with weak bond strength on the surface of Co3 O4-N2-200, which was ready to adsorb formaldehyde to form bidentate formate, and then decompose to products via monodentate formate. With increasing pretreatment temperature, the amount of negative oxygen ions decreased, accordingly the catalytic activity for formaldehyde catalytic oxidation decreased due to slow decomposition rate of desorbed bidentate formate.