Nanostructured Pr-Rich CexPr1-xO2-δ Mixed Oxides for Diesel Soot Combustion: Importance of Oxygen Lability

Author:

Mekki Imene1,Grzybek Gabriela2ORCID,Kotarba Andrzej2ORCID,García-García Avelina1ORCID

Affiliation:

1. Carbon Materials and Environment Research Group (MCMA), Department of Inorganic Chemistry and Institute of Materials, University of Alicante, Carretera de San Vicente del Raspeig, s/n, 03690 Alicante, Spain

2. Faculty of Chemistry, Jagiellonian University in Kraków, Gronostajowa 2, 30-387 Krakow, Poland

Abstract

Soot combustion experiments with 5%O2/He were conducted using model soot, and four distinct compositions of CexPr1-xO2-δ oxides of varying nominal cerium compositions (x = 0, 0.2, 0.3, and 1) were prepared. The catalyst samples were comprehensively characterized using techniques such as XRD, Raman spectroscopy, HR-TEM, N2 adsorption at −196 °C, XPS, O2-TPD, H2-TPR, and work function measurements. The Pr-rich compositions, ranging from Ce0.3Pr0.7O2-δ to PrO2-δ, resulted in a significant increase in the total evolved O2 amounts and enhanced catalyst reducibility. However, a decrease in the textural properties of the catalysts was noted, which was particularly important for the pure praseodymia under the synthesis route conducted. The catalytic activity was investigated under the two following contact modes of mixing between soot and catalyst: loose and tight. The results revealed that the catalytic performance is associated with the surface contact in tight contact mode and with the combination of surface/subsurface/bulk oxygen mobility and the BET surface area in loose contact mode. Notably, the temperatures estimated at 10% and 50% of the conversion (T10 and T50) parameters were achieved at much lower temperatures than the uncatalyzed soot combustion, even under loose contact conditions. Specifically, the 50% conversion was achieved at 511 °C and 538 °C for Ce0.3Pr0.7O2 and Ce0.2Pr0.8O2, respectively. While no direct correlation between catalytic activity and work function was observed, a significant relationship emerges between work function values and the formation of oxygen vacancies, whatever the conditions used for these measurements. On the other hand, the ability to generate a high population of oxygen vacancies at low temperatures, rather than the direct activation of gas-phase O2, influences the catalytic performance of Pr-doped ceria catalysts, highlighting the importance of surface/subsurface oxygen vacancy generation, which was the parameter that showed a better correlation with the catalytic activity, whatever the soot conversion value or the mode of contact considered.

Funder

Spanish Ministry of Science and Innovation/Research Spanish Agency

UE-FEDER funding, and Generalitat Valenciana

Algerian Ministry of Higher Education and Scientific Research

Publisher

MDPI AG

Reference40 articles.

1. Nakagoshi, Y., Mori, K., Tanaka, K., Furuta, Y., Aoki, T., Yoshioka, F., and Kato, K. (2023). New Generation Diesel Particulate Filter for Future Euro7 Regulation, SAE International.

2. (2023, November 15). Commission Proposes New Euro 7 Standards. Available online: https://ec.europa.eu/commission/presscorner/detail/en/ip_22_6495.

3. Lou, D., Chen, Y., Zhang, Y., Wan, P., Tan, P., Hu, Z., Fang, L., and Wang, T. (2023). Study on Soot Oxidation Characteristics of Ce and La Modified Pt-Pd CDPF Catalysts, SAE International.

4. Layered Na2Mn3O7 Decorated by Cerium as the Robust Catalysts for Efficient Low Temperature Soot Combustion;Yu;Appl. Catal. B Environ.,2023

5. (2023, October 31). Euro 7: MEPs Back New Rules to Reduce Road Transport Emissions|Nyheter|Europaparlamentet. Available online: https://www.europarl.europa.eu/news/sv/press-room/20231009IPR06746/euro-7-meps-back-new-rules-to-reduce-road-transport-emissions.

Cited by 3 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3