配对
铈
硫黄
Atom(片上系统)
化学
原子物理学
无机化学
物理
凝聚态物理
有机化学
工程类
超导电性
嵌入式系统
作者
Xue Fang,Tian Qin,Junxiao Chen,Zhen Ma,Xi Liu,Xingfu Tang
标识
DOI:10.1021/acs.est.4c02997
摘要
Environmentally benign cerium-based catalysts are promising alternatives to toxic vanadium-based catalysts for controlling NOx emissions via selective catalytic reduction (SCR), but conventional cerium-based catalysts unavoidably suffer from SO2 poisoning in low-temperature SCR. We develop a strongly sulfur-resistant Ce1+1/TiO2 catalyst by spatially confining Ce atom pairs to different anchoring sites of anatase TiO2(001) surfaces. Experimental results combined with theoretical calculations demonstrate that strong electronic interactions between the paired Ce atoms upshift the lowest unoccupied states to an energy level higher than the highest occupied molecular orbital (HOMO) of SO2 so as to be catalytically inert in SO2 oxidation but slightly lower than HOMO of NH3 so that Ce1+1/TiO2 has desired ability toward NH3 activation required for SCR. Hence, Ce1+1/TiO2 shows higher SCR activity and excellent stability in the presence of SO2 at low temperatures with respect to supported single Ce atoms. This work provides a general strategy to develop sulfur-resistant catalysts by tuning the electronic states of active sites for low-temperature SCR, which has implications for practical applications with energy-saving requirements.
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