当前位置: X-MOL 学术Appl. Catal. A Gen. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A new understanding of CeO2-ZrO2 catalysts calcinated at different temperatures: Reduction property and soot-O2 reaction
Applied Catalysis A: General ( IF 4.7 ) Pub Date : 2018-07-11 , DOI: 10.1016/j.apcata.2018.07.012
Hailong Zhang , Wei Hu , Caixia Zhou , Hongrui Liu , Peng Yao , Jianli Wang , Yaoqiang Chen

CexZr(1-x)O2 (x = 0.27, 0.50 and 0.73) mixed oxides were prepared by co-precipitation method and then aged at 700–1000 °C. The reducibility of the aged catalysts was investigated by H2-TPR. It was found that the changes in reduction properties are related to the Ce/Zr ratio and Ce0.27Zr0.73O2 shows an increased H2 consumption with aging temperature increasing, even 1000 °C-aged samples show an increased reduction ability. Raman, XPS and HRTEM reveal that the promotion on reduction property of the aged samples should be ascribed to the increase of surface oxygen species, surface Ce/Zr ratio, O-vacancies and (110) and (100) planes. However, this promotion can not obviously improve soot oxidation activity. XRD, BET and O2-TPD results reveal that textural, structural and oxygen desorption properties are crucial to soot oxidation activity. The poor contact between soot and active sites would be an important factor that leads to a contradiction between H2-TPR and soot-O2 reaction activity.



中文翻译:

对在不同温度下煅烧的CeO 2 -ZrO 2催化剂的新认识:还原性能和碳烟O 2反应

通过共沉淀法制备了Ce x Zr (1-x) O 2(x = 0.27、0.50和0.73)混合氧化物,然后在700–1000°C时效。通过H 2 -TPR研究了老化催化剂的还原性。发现还原性能的变化与Ce / Zr比有关,并且Ce 0.27 Zr 0.73 O 2显示出增加的H 2。随着时效温度的升高,即使是1000°C时效的样品,其还原能力也会提高。Raman,XPS和HRTEM表明,老化样品还原性能的提高应归因于表面氧种类,表面Ce / Zr比,O空位以及(110)和(100)平面的增加。但是,这种促进不能明显改善烟灰的氧化活性。XRD,BET和O 2 -TPD结果表明,结构,结构和氧解吸性质对烟ot氧化活性至关重要。烟灰与活性位点之间的不良接触将是导致H 2 -TPR与烟灰-O 2反应活性之间矛盾的重要因素。

更新日期:2018-07-11
down
wechat
bug