Synergy of Single-Atom Fe1 and Ce–Ov Sites on Mesoporous CeO2–Al2O3 for Efficient Selective Catalytic Reduction of NO with CO,ACS Catalysis

当前位置： X-MOL 学术 › ACS Catal. › 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.)

Synergy of Single-Atom Fe1 and Ce–Ov Sites on Mesoporous CeO2–Al2O3 for Efficient Selective Catalytic Reduction of NO with CO
ACS Catalysis ( IF 11.3 ) Pub Date : 2024-01-03 , DOI: 10.1021/acscatal.3c04682
Yuting Bai ₁ , Xupeng Zong ₁ , Chengwen Jin ₁ , Shudong Wang ₁ , Sheng Wang ₁

Affiliation

Nonprecious transition-metal oxides, especially Fe-, Cu-, Co-, and Mn-containing mixed oxides, have been regarded as promising alternatives for noble metal catalysts for the abatement of NO_x contamination. However, the identification of the real catalytically active sites for these mixed oxides remains unclear in most cases, which limits our in-depth understanding of the intrinsic mechanism. Here, we comprehensively investigated an iron–cerium–aluminum oxide (Fe₁/CeO₂–Al₂O₃) prepared with a co-precipitation method. Structural identification confirmed that Fe sites are atomically dispersed, bonding with four O atoms in the first coordination shell and with two Ce atoms in the second shell on average. Highly efficient removal of NO with 100% selectivity toward N₂ has been achieved over these sites at a temperature as low as 250 °C. In situ characterizations and computational studies revealed that the high activity and N₂ selectivity of Fe₁/CeO₂–Al₂O₃ can be attributed to the synergetic effect of the single-atomic Fe₁ site and surrounding Ce–O_v, which intensively promotes the adsorption of NO molecules and N₂O intermediates. Subsequently, Ce–O_v facilitates the N–O dissociation toward N₂ and then is regenerated with CO, forming CO₂ as a product. The present results provide valuable insights into the mechanism of transition-metal oxide catalysts for the NO–CO reaction and offer useful guidance for designing catalysts with high activity and selectivity.

中文翻译：

介孔 CeO2-Al2O3 上单原子 Fe1 和 Ce-Ov 位点的协同作用，用于 CO 高效选择性催化还原 NO

_{非贵金属过渡金属氧化物，特别是含Fe、Cu、Co和Mn的混合氧化物，已被认为是用于减少NO x}污染的贵金属催化剂的有前途的替代品。然而，在大多数情况下，这些混合氧化物真正的催化活性位点的识别仍不清楚，这限制了我们对其内在机制的深入理解。在这里，我们全面研究了用共沉淀法制备的铁-铈-铝氧化物（Fe ₁ /CeO ₂ -Al ₂ O _{3 ）。}结构鉴定证实Fe位点是原子分散的，平均与第一配位层中的四个O原子成键，并与第二个配位层中的两个Ce原子成键。在低至 250 °C 的温度下，这些位点已经实现了对 N ₂具有 100% 选择性的高效去除 NO 。原位表征和计算研究表明，Fe ₁ /CeO ₂ –Al ₂ O _{3的高活性和 N}₂选择性可归因于单原子 Fe ₁位点和周围 Ce-O _v的协同效应，这强烈促进NO分子和N ₂ O中间体的吸附。随后，Ce-O _v促进N-O解离成N ₂，然后用CO再生，形成CO ₂作为产物。目前的结果为了解过渡金属氧化物催化剂用于NO-CO反应的机理提供了有价值的见解，并为设计具有高活性和选择性的催化剂提供了有用的指导。

更新日期：2024-01-03

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南