Mn掺杂对尖晶石型NiFe1.97Pd0.03O4-δ催化剂脱硝性能的影响

采用生物模板法，通过掺杂Mn对尖晶石型NiFe_1.97Pd_0.03O_4-δ催化剂中的Fe离子进行取代，制备一系列不同Mn掺杂量的NiFe_1.97-xMn_xPd_0.03O_4-δ催化剂（x=0、0.01、0.02、0.05、0.10），并在单管固定床反应器中进行H₂-SCR脱硝性能评价。运用X射线衍射仪（XRD）、场发射扫描电子显微镜（FE-SEM）、程序升温-脱附（NH₃-TPD）和程序升温还原（H₂-TPR）以及傅里叶红外光谱仪（FTIR）等手段对催化剂进行表征、分析。结果表明：适量Mn的掺杂不仅可以提高活性物种Pd在催化剂上的分散度，还显著提高了其催化剂表面的总酸量及其氧化还原能力，从而提高了NiFe_1.97Pd_0.03O_4-δ催化剂在低温下的H₂-SCR脱硝活性，并拓宽了其催化活性温度窗口。在实验范围内，NiFe_1.92Mn_0.05Pd_0.03O_4-δ催化剂在150℃下的NO转化率高达95%，且在150~200℃温度区间内，NO转化率均在90%以上。

Effect of Mn-doped spinel catalyst NiFe1.97Pd0.03O4-δon catalytic performance for SCR

Spinel catalyst NiFe_1.97-xMn_xPd_0.03O_4-δ was prepared by using a biological template and then was applied for the selective catalytic reduction of NO with hydrogen(H₂-SCR) in a single-tube fix-bed reactor. A series of spinel catalysts was obtained by doping Mn with different molar ratio of Mn to Ni. The catalysts were characterized by X-ray diffraction（XRD）, field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy（FTIR）, NH₃ temperature-programmed desorption (NH₃-TPD) and H₂ temperature-programmed reduction (H₂-TPR). The results indicated that the catalysts doped with suitable amount of Mn had significantly improved the dispersion of the active specie Pd, the total acid content on the catalyst surface and the ability to oxidation, leading to enhanced de-NO_xperformance of NiFe_1.97Pd_0.03O_4-δcatalyst at low temperature and a broadened active temperature window. Within the scope of the experiments, the NO conversion of NiFe_1.92Mn_0.05Pd_0.03O_4-δcatalyst was up to 95% at 150℃, and maintained above 90% at 150—200℃.