NaBH4处理LaCuZn X(X=Zr、Al、Zr+Al)(类)钙钛矿型催化剂及其CO 2加氢合成甲醇性能的研究  

LaCuZn X(X=Al,Zr,Al+Zr)perovskite-like catalysts treated by NaBH 4 and their catalytic performance for CO 2 hydrogenation to methanol

作　　者：匡志奇 李枫[1] 雒京 王烟霞 袁丹萍 王琴[1,2] 赵海宏 王世威 赵宁 肖福魁[1] KUANG Zhi-qi;LI Feng;LUO Jing;WANG Yan-xia;YUAN Dan-ping;WANG Qin;ZHAO Hai-hong;WANG Shi-wei;ZHAO Ning;XIAO Fu-kui(State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049

出　　处：《燃料化学学报》2020年第3期293-301,I0003,共10页Journal of Fuel Chemistry and Technology

基　　金：国家青年科学基金(21802158);国家自然科学基金(21776294);山西省自然科学基金(201801D121070);山西省青年科学基金(201701D221052)资助。

摘　　要：通过并流沉淀法制备出La∶Cu∶Zn∶X(X=Zr、Al、Zr+Al)(类)钙钛矿型催化剂,并使用NaBH 4作为还原剂进行液相还原。将催化剂装填在固定床反应器中并用于CO 2加氢制甲醇的性能评价,并通过一系列表征方法对催化剂的物化性能进行了测试。结果表明,所制备的催化剂主要具有La 2CuO 4(类)钙钛矿结构,并且在该结构中掺入元素后将导致(类)钙钛矿结构的空间扭曲。经NaBH 4还原后,结构中存在金属铜物种和部分未还原的高价态铜物种,在反应过程中会发生高价态铜物种的还原。相比于LaCuZn催化剂,Al元素的引入提高了CO 2的转化率,Zr元素的引入,降低了催化剂的催化活性,Al和Zr元素同时引入提高了CO 2转化率和甲醇的收率。LCZA催化剂CO 2转化率最高,LCZ催化剂甲醇选择性最高,LCZZA催化剂甲醇时空收率最高。CO 2转化率和催化剂的Cu的比表面积、Cu的分散度、(Cu^α++Cu^0)/Cu total呈正相关;催化剂Cuα+的结合能越远离Cu^+,相应催化剂的甲醇选择性越高。La∶Cu∶Zn∶X(X=Zr,Al,Al+Zr)perovskite-like catalysts were prepared by coprecipitation method followed by liquid phase reduction by NaBH 4.The physicochemical properties of the catalysts were tested by a series of characterization methods,and the catalysts were tested for methanol synthesis from CO 2 hydrogenation in a fixed-bed reactor.The results showed that the as-prepared catalysts were mainly composed of La 2CuO 4 perovskite-like crystal structure and doping of elements led to the spatial distortion of the perovskite-like structure.After reduction by NaBH 4,metal copper species and some high-valence copper species were found,which could be further reduced during the reaction.The CO 2 conversion was positively correlated with the Cu surface area,the dispersion of Cu,and the(Cu^α++Cu^0)/Cu total of the catalyst.The higher methanol selectivity was obtained when Cuα+binding energy was farther away from Cu^+binding energy.LCZA had the highest CO 2 conversion,LCZ catalyst possessed the highest methanol selectivity,and LCZZA catalyst presented the optimal methanol space time yield.

关 键 词：CO2加氢 甲醇 (类)钙钛矿 液相还原 

分 类 号：O643[理学—物理化学]