锂改性Pd/C催化剂及其乙炔氢氯化催化性能

石油天然气精细化工教育部新疆维吾尔自治区省部共建重点实验室,新疆 乌鲁木齐 830046

锂改性; 钯催化剂; 催化性能; 活性炭

Li doped Pd/C catalyst and its catalyticperformance for acetylene hydrochlorination
WU Dong,WANG Feng,WANG Ji-de,WANG Lu

(Key Laboratory of Oil & Gas Fine Chemicals of Ministry of Education & Xinjiang Uyghur Autonomous Region,Urumqi 830046,China)

Li promoter; Pd catalyst; catalytic performances; active carbon

DOI: 10.13800/j.cnki.xakjdxxb.2017.0317

备注

以活性炭为载体,LiCl溶液和PdCl2溶液为改性剂和活性组分前驱体,分别用共浸渍法和分步浸渍法制备了Li改性Pd/C催化剂并将其应用于乙炔氢氯化反应,考察了制备方法和助剂负载量对催化剂性能的影响。结果 表明,制备方法和助剂负载量均会影响催化剂在乙炔氢氯化反应中的催化活性,LiCl与PdCl2共浸渍所制备的催化剂,Li负载量为0.5%时催化剂催化性能最佳,乙炔转化率达99%的高活性可维持2 h以上,氯乙烯选择性可达97%.对催化剂进行BET,TG,XRD,TPR,XPS和FT-IR对催化剂表征分析。发现,适量Li添加改性提高了催化剂中活性组分钯物种的分散度,减少了催化剂表面积碳的生成,抑制了钯活性组分的还原,从而改善了催化剂的活性和稳定性。

Li modified Pd/AC catalysts were prepared by co-impregnation and step impregnation.LiCl and PdCl2 were used as promoter and active component precursor,respectively,applying to acetylene hydrochlorination,and the catalytic performances of the catalysts were tested.It is found that catalytic performances were influenced by the preparation methods and Li loading amount.The results show that the catalysts,which prepared by co-impregnation and loaded 0.5%(wt)of Li promoter,exhibited the best performances:more than 99% of acetylene conversion during 2 h reaction time and around 97% selectivity of VCM.BET,XRD,TPR,TG,XPS and FT-IR characterization analysis showed that moderate Li additive could promote the activity and the stability of the catalyst result from the improvement of the dispersion of Pd species at the catalysis,decrease the coke deposition,and restrict the reduction of active component Pd.