NOx Storage Performance at Low Temperature over Platinum Group Metal-Free SrTiO3-Based Material
NOx Storage Performance at Low Temperature over Platinum Group Metal-Free SrTiO3-Based Material
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无铂族金属 SrTiO3 基材料的低温 NOx 存储性能
DOI：
10.1021/acsami.1c03465
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发表时间：
2021
影响因子：
9.5
通讯作者：
Tanaka Tsunehiro
中科院分区：
文献类型：
--
作者：
Yoshiyama Yuji;Hosokawa Saburo;Tamai Kazuki;Kajino Takanobu;Yoto Hiroaki;Asakura Hiroyuki;Teramura Kentaro;Tanaka Tsunehiro
Pt基催化剂通常用作汽车的NOx捕集催化剂，而钙钛矿氧化物作为无Pt的NOx捕集催化剂而受到关注。然而，钙钛矿催化剂的氮氧化物存储性能在低温和共存气体（例如H2O、CO2和SO2）下明显较差。这项研究表明，NOx 存储反应在氧化还原位点（Mn、Fe 和 Co）掺杂的 SrTiO3 钙钛矿上进行。在所测试的催化剂中，Mn掺杂的SrTiO3表现出最高的NOx存储能力（NSC），即使在323 K的低温下也表现出较高的NSC。此外，Mn掺杂的SrTiO3在有毒气体（H2O、CO2和SO2）存在下仍保持高NOx存储性能。 NO氧化实验表明，Co掺杂SrTiO3的NSC依赖于通过晶格氧从NO到NO2的NO氧化活性，这导致低温下NSC较差。另一方面，Mn 掺杂的 SrTiO3 在 323 K 下成功地将 NO 分子吸附到其表面，而无需使用晶格氧进行 NO 氧化过程。 Mn 掺杂 SrTiO3 的这种独特吸附行为被认为是有毒气体存在下高 NSC 的原因。
Pt-based catalysts are commonly employed as NOx-trapping catalysts for automobiles, while perovskite oxides have received attention as Pt-free NOx-trapping catalysts. However, the NOxstorage performance of perovskite catalysts is significantly inferior at low temperatures and with coexisting gases such as H2O, CO2, and SO2. This study demonstrates that NOxstorage reactions proceed over redox site (Mn, Fe, and Co)-doped SrTiO3perovskites. Among the examined catalysts, Mn-doped SrTiO3exhibited the highest NOxstorage capacity (NSC) and showed a high NSC even at a low temperature of 323 K. Moreover, the high NOxstorage performance of Mn-doped SrTiO3was retained in the presence of poisoning gases (H2O, CO2, and SO2). NO oxidation experiments revealed that the NSC of Co-doped SrTiO3was dependent on the NO oxidation activity from NO to NO2via lattice oxygen, which resulted in an inferior NSC at low temperatures. On the other hand, Mn-doped SrTiO3successfully adsorbed NO molecules onto its surface at 323 K without the NO oxidation process using lattice oxygens. This unique adsorption behavior of Mn-doped SrTiO3was concluded to be responsible for the high NSC in the presence of poisoning gases.