CAJ | 학술논문

采用X射线衍射、热重、NH_3程序升温脱附、CO_2程序升温脱附等手段研究了Al_2_3,MgO,CaO和KNO_3改性MgO催化剂的结构和酸碱性质,并在固定床反应装置上考察了上述催化剂气相催化转化1,2-丙二醇反应性能.结果表明,催化剂表面的酸碱性对1,2-丙二醇气相转化反应的产物分布有显著影响.A1_2O_3催化剂上的产物以丙醛和丙酮为主;MgO催化剂上的主要产物为丙酮醇:CaO催化剂上丙酮和丙烯醇选择性相对较高;KNO_3改性MgO催化剂上环氧丙烷选择性显著升高.结合不同催化剂酸碱性质及其反应结果,提出了1,2-丙二醇气相转化的6个主要反应途径,明确了各反应途径与催化剂酸碱性质的关系.
채용X사선연사、열중、NH_3정서승온탈부、CO_2정서승온탈부등수단연구료Al_2_3,MgO,CaO화KNO_3개성MgO최화제적결구화산감성질,병재고정상반응장치상고찰료상술최화제기상최화전화1,2-병이순반응성능.결과표명,최화제표면적산감성대1,2-병이순기상전화반응적산물분포유현저영향.A1_2O_3최화제상적산물이병철화병동위주;MgO최화제상적주요산물위병동순:CaO최화제상병동화병희순선택성상대교고;KNO_3개성MgO최화제상배양병완선택성현저승고.결합불동최화제산감성질급기반응결과,제출료1,2-병이순기상전화적6개주요반응도경,명학료각반응도경여최화제산감성질적관계.
The structure and surface acid-base properties of Al_2O_(3-), CaO-, MgO-, and KNO_(3-)modified MgO catalysts were characterized by X-ray diffraction, thermogravimetry, NH_3 temperature-programmed desorption, and CO_2 temperature-programmed desorption. The catalysts were applied to catalyze the gas-phase transformation of propylene glycol in a fixed-bed reactor. The results indicated that the catalytic performance of these catalysts significantly depended on the surface acid-base properties. Main products detected were propionaldehyde and acetone on Al_2O_3, acetol on MgO, and acetone and allyl alcohol on CaO. However, the MgO catalyst modified with KNO_3 remarkably enhanced the selectivity for propylene oxide. A six-pathway reaction mechanism was proposed to describe the catalytic transformation of propylene glycol based on the acid-base properties and the reaction results of the catalysts.