Yu Dezhong, Zhong Xin, Liu Dong, Liang Ying
School of Chemistry and Environmental Engineering, Wuhan Institute of Technology Wuhan 430205 China
School of Chemical Engineering, Hubei University of Arts and Science Xiangyang 441053 China.
RSC Adv. 2019 Oct 10;9(55):32232-32239. doi: 10.1039/c9ra03956b. eCollection 2019 Oct 7.
BiO/CoO catalysts prepared by the impregnation method were investigated for the selective catalytic reduction of NO by CH (CH-SCR) in the presence of O. Their physicochemical properties were analyzed with SEM, XRD, H-TPR, XPS, PL and IR measurements. It was found that the deposition of BiO on CoO nanoplates enhanced the catalytic activity, especially at low reaction temperature. The SO tolerance of CoO in CH-SCR activity was also improved with the addition of BiO. Among all catalysts tested, 10.0 wt% BiO/CoO achieved a 90% NO conversion at 200 °C with the total flow rate of 200 mL min (GHSV 30 000 h). No loss in its CH-SCR activity was observed at different temperatures after the addition of 100 ppm of SO to the reaction mixture. These enhanced catalytic behaviors may be associated with the improved oxidizing characteristics of 10.0 wt% BiO/CoO. XRD results showed that BiO entered the lattice of CoO, resulting in the formation of lattice distortion and structural defects. H-TPR results showed that the reduction of CoO was promoted and the diffusion of oxygen was accelerated with the addition of BiO. XPS measurements implied that more Co formed on the 10.0% BiO/CoO catalysts. The improved oxidizing characteristics of the catalyst with the addition of BiO due to the synergistic effect of the nanostructure hybrid, thus enhanced the CH-SCR reaction and hindered the oxidization of SO. Therefore, the 10.0% BiO/CoO catalyst exhibited the highest NO conversion and strongest SO tolerance ability.
研究了通过浸渍法制备的BiO/CoO催化剂在O存在下用于CH选择性催化还原NO（CH-SCR）的性能。采用扫描电子显微镜（SEM）、X射线衍射（XRD）、程序升温还原（H-TPR）、X射线光电子能谱（XPS）、光致发光（PL）和红外光谱（IR）测量对其物理化学性质进行了分析。结果发现，BiO沉积在CoO纳米片上提高了催化活性，尤其是在低反应温度下。添加BiO后，CoO在CH-SCR活性中的抗SO性能也得到了改善。在所有测试的催化剂中，10.0 wt%的BiO/CoO在200℃、总流速为200 mL min（空速30000 h）时实现了90%的NO转化率。在反应混合物中添加100 ppm的SO后，在不同温度下均未观察到其CH-SCR活性的损失。这些增强的催化行为可能与10.0 wt%的BiO/CoO氧化特性的改善有关。XRD结果表明，BiO进入了CoO的晶格，导致晶格畸变和结构缺陷的形成。H-TPR结果表明，添加BiO促进了CoO的还原并加速了氧的扩散。XPS测量表明，在10.0%的BiO/CoO催化剂上形成了更多的Co。由于纳米结构杂化物的协同效应，添加BiO后催化剂的氧化特性得到改善，从而增强了CH-SCR反应并阻碍了SO的氧化。因此，10.0%的BiO/CoO催化剂表现出最高的NO转化率和最强的抗SO能力。
