磷助剂对K_2WO_4/Al_2O_3催化合成甲硫醇的影响

采用溶胶凝胶法,并引入不同含量的磷助剂,制备了K_2WO_4/P_xAl_2O_3催化剂,采用XRD、N_2吸附-脱附、FTIR、原位吡啶吸附FTIR和NH_3/CO_2-TPD等技术,考察磷含量对催化剂结构和酸碱性质及催化甲醇与硫化氢反应性能的影响。表征结果显示,随磷含量(w)由0.5%增至4.0%,催化剂的比表面积变化不大,而平均孔径和孔体积略有增加,催化剂活性组分的晶粒变小;含磷助剂的催化剂表面不含B酸,随磷含量的增加,催化剂的表面酸强度先增强后减弱,而碱量降低;在磷含量为1%(w)时,催化剂的活性最高,比不含磷的催化剂高约2.3%。

Effects of Phosphorus Promoter on K2WO4/Al2O3 Catalysts for Synthesis of Methanethiol

Phosphorus-promoted K_2WO_4/Al_2O_3 catalysts for the synthesis of methanethiol from methanol and H_2S were prepared and characterized by means of BET,XRD,FTIR,in situ pyridine adsorption FTIR and NH_3/CO_2-TPD.The characterization results revealed that with the increase of the P content in the catalysts in the range from 0.5%to 4.0%(w),the crystallite sizes of the catalysts decreased,the pore volume and average pore size increased,while the specific surface area showed little changing.With increasing the P dosage,the acidity of the catalysts first increased and then decreased,while the basicity decreased.The highest catalytic activity of the catalyst in the reaction can be obtained when the P content in the catalyst is 1%(w),with the catalytic activity being 2.3% higher than that of K_2WO_4/Al_2O_3 catalyst without P.