[Optimization of Promoter and Support for Co-based/zeolites Catalysts in Catalytic Reduction of NO x by CH4]
Pan, H; Jian, YF; Chen, NN; Liu, HX; He, C; He, YF
| HERO ID | 4750239 |
|---|---|
| In Press | No |
| Year | 2017 |
| Title | [Optimization of Promoter and Support for Co-based/zeolites Catalysts in Catalytic Reduction of NO x by CH4] |
| Authors | Pan, H; Jian, YF; Chen, NN; Liu, HX; He, C; He, YF |
| Journal | Huanjing Kexue / Chinese Journal of Environmental Science |
| Volume | 38 |
| Issue | 7 |
| Page Numbers | 3085-3094 |
| Abstract | Catalytic behavior of Co-based/zeolites catalysts was investigated in NO x reduction by CH4. Optimization of promoter and support was investigated by catalytic tests, and the relationship between catalytic activity and catalyst structure was illustrated by catalyst characterization. Co-Fe/SAPO-34 exhibited the highest activity among various Co-base/zeolites catalysts. The maximum conversion of NO x with 52.7% was obtained on Co-Fe/SAPO-34 at 450℃. The inhibition of activity of Fe/zeolites became severe in the presence of SO2, CO2, and H2O. CO2 exerted virtually no effect on the SCR activity of Co-Fe/zeolites. The inhibition of NO x conversion by H2O was reversible for Co-Fe/zeolites catalysts. Cobalt species were mainly present in CoO and Co(OH)2 states in Co-Fe/SAPO-34. Co3O4and Co(OH)2 were the main cobalt species of Co-Fe/ZSM-5, while CoO, CoAl2O4 and Co3O4 might be present in Co-Fe/Beta. The ratio of Fe2+/Fe3+ in the surface layer of Co-Fe/zeolites decreased in the order of Co-Fe/ZSM-5(3.98) > Co-Fe/SAPO-34(0.52) > Co-Fe/Beta(0.43). The active states of cobalt species and suitable ratio of Fe2+/Fe3+ were important for the activity of Co-Fe/zeolites in CH4-SCR. CH4-SCR over Co-Fe/zeolite catalysts started with the adsorption of NO and CH4 on Brønsted acid sites of the zeolite to produce NO+and carbon-containing species(-C=O and -COO) in the presence of oxygen, respectively. Subsequently, the important intermediates of nitrate species were generated from NO+ at the active sites. Finally, nitrate species reacted with carbon-containing species to form N2 and CO2. |
| Doi | 10.13227/j.hjkx.201610195 |
| Pmid | 29964653 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | Chinese |