Khan Mehak Nawaz, Han Lupeng, Wang Penglu, Zhang Dengsong
State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Research Center of Nano Science and Technology, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.
State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, Research Center of Nano Science and Technology, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.
iScience. 2020 Jun 26;23(6):101173. doi: 10.1016/j.isci.2020.101173. Epub 2020 May 18.
It is still challenging to develop strongly alkali-resistant catalysts for selective catalytic reduction of NO with NH. It is generally believed that the maintenance of acidity is the most important factor because of neutral effects of alkali. This work discovers that the redox properties rather than acidity play decisive roles in improving alkali resistance of some specific catalyst systems. K-poisoned Fe-decorated SO-modified CeZr oxide (Fe/SO/CeZr) catalysts show decreased acidity but reserve the high redox properties. The higher reactivity of NH species induced by K poisoning compensates for the decreased amount of adsorbed NH, leading to a desired reaction efficiency between adsorbed NH and nitrate species. This study provides a unique perspective in designing an alkali-resistant deNO catalyst via improving redox properties and activating the reactivities of NH species rather than routinely increasing acidic sites for NH adsorption, which is of significance for academic interests and practical applications.
开发用于氨选择性催化还原一氧化氮的强耐碱催化剂仍然具有挑战性。一般认为，由于碱的中和作用，保持酸性是最重要的因素。这项工作发现，氧化还原性质而非酸性在提高某些特定催化剂体系的耐碱性方面起决定性作用。钾中毒的铁修饰的SO改性铈锆氧化物（Fe/SO/CeZr）催化剂酸性降低，但保留了高氧化还原性质。钾中毒诱导的NH物种更高的反应活性补偿了吸附NH量的减少，导致吸附的NH与硝酸盐物种之间具有理想的反应效率。本研究为设计耐碱脱硝催化剂提供了一个独特的视角，即通过改善氧化还原性质和激活NH物种的反应活性，而不是常规地增加用于NH吸附的酸性位点，这对学术研究和实际应用具有重要意义。
