Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, Sichuan, China.
College of Chemistry and Chemical Engineer, Xiamen University, Xiamen, 361005, Fujian, China.
Environ Sci Pollut Res Int. 2021 May;28(20):26018-26029. doi: 10.1007/s11356-020-11918-2. Epub 2021 Jan 22.
This work assessed the impact of biodiesel impurities on CeO catalyst for soot combustion via soot-TPO experiments. The results showed that Na- and K-doped catalysts were assisted for soot combustion, while Ca- and P-doped catalysts had a negative effect. N adsorption-desorption and XRD results indicated that doping biodiesel impurities led to smaller surface area by blocking small pores. Surface chemical properties are suggested as major reasons for promoting soot combustion by means of XPS, H-TPR, and O-TPD. Na- and K-doped catalysts showed stronger redox ability and surface lattice oxygen mobility, poorly for Ca- and P-doped catalysts. Interestingly, a large number of surface oxygen species were observed on P-doped catalyst and it enhanced the ignition of bio soot. In the presence of NO, surface chemical properties including NO storage/release capacity and NO oxidation ability were characterized by NO-adsorption DRIFTS, NO-TPO and NO-desorption DRIFTS, alkali-doped catalyst with excellent NO storage capacity that can release active oxygen species and gaseous NO accelerate heterogeneous soot combustion, and the poor NO conversion ability to NO that weakens the promotion effect of soot combustion. Particularly in the existence of P, the promotion effect of soot elimination in NO + O was further weakened by the reason of poor NO storage capacity and NO oxidation ability.
本工作通过 soot-TPO 实验评估了生物柴油杂质对 CeO 催化剂用于烟尘燃烧的影响。结果表明，Na 和 K 掺杂的催化剂有助于烟尘燃烧，而 Ca 和 P 掺杂的催化剂则产生负面影响。N 吸附-解吸和 XRD 结果表明，掺杂生物柴油杂质通过阻塞小孔导致比表面积减小。XPS、H-TPR 和 O-TPD 表明表面化学性质是促进烟尘燃烧的主要原因。Na 和 K 掺杂的催化剂表现出更强的氧化还原能力和表面晶格氧迁移率，而 Ca 和 P 掺杂的催化剂则较差。有趣的是，在 P 掺杂的催化剂上观察到大量表面氧物种，这增强了生物烟尘的点火。在存在 NO 的情况下，通过 NO 吸附 DRIFTS、NO-TPO 和 NO 解吸 DRIFTS 对表面化学性质（包括 NO 储存/释放能力和 NO 氧化能力）进行了表征，具有优异 NO 储存能力的碱掺杂催化剂可以释放活性氧物种和气态 NO 加速异相烟尘燃烧，而对 NO 的较差的 NO 转化能力削弱了烟尘燃烧的促进作用。特别是在 P 的存在下，由于较差的 NO 储存能力和 NO 氧化能力，NO+O 中烟尘消除的促进作用进一步减弱。
