论文部分内容阅读
在TiO2负载的锰氧化物(MnOx/TiO2)中引入第2种组分,制成二元金属氧化物(MnOx-A/TiO2)催化剂,A分别为Fe2O3、WO3、MoO3、Cr2O3,试验研究低温催化活性、N2选择性及抗SO2毒性。结果表明,低温催化活性从高到低依次为:Mn-W/TiO2>Mn-Fe/TiO2>Mn-Cr/TiO2>Mn-Mo/TiO2;N2选择性:Mn-Fe/TiO2>Mn-W/TiO2>Mn-Mo/TiO2>Mn-Cr/TiO2,Mn-Fe/TiO2和Mn-W/TiO2保持了较高低温催化活性的同时提高了N2选择性。当反应气中含有&(SO2)=0.01%和&(H2O)=6%,空速为12600h-1、120℃、8h后NOx转化率Mn-W/TiO2、Mn-Fe/TiO2、Mn-Mo/TiO2分别保持在98.5%、95.8%及94.2%。由此得出,WO3、Fe2O3为MnOx有效的助催化剂,可大大提高MnOx/TiO2的选择性和抗SO2毒性的能力。傅里叶变换红外光谱显示,与Fe2O3不同,WO3也提供了部分Lewis酸活性点,说明在有低浓度SO2存在下,Mn-W/TiO2显示了极好的低温NH3选择性还原NOx的催化活性。
The second component was introduced into the manganese oxide (MnOx / TiO2) supported on TiO2 to make the binary metal oxide (MnOx-A / TiO2) catalyst. A was Fe2O3, WO3, MoO3 and Cr2O3 respectively. Catalytic activity, N2 selectivity and anti-SO2 toxicity. The results showed that the catalytic activities at low temperature ranged from high to low: Mn-W / TiO2> Mn-Fe / TiO2> Mn-Cr / TiO2> Mn-Mo / TiO2; N2 selectivity: Mn-Fe / TiO2> Mn-W / TiO2> Mn-Mo / TiO2> Mn-Cr / TiO2, Mn-Fe / TiO2 and Mn-W / TiO2 keep higher catalytic activity at low temperature and improve N2 selectivity. When the reaction gas contains (SO2) = 0.01% and (H2O) = 6%, the space velocity is 12600h-1,120 ℃, the conversion of NOx to Mn-W / TiO2, Mn-Fe / TiO2 and Mn- Mo / TiO2 remained at 98.5%, 95.8% and 94.2% respectively. Thus, WO3, Fe2O3 MnOx effective cocatalyst, can greatly improve the MnOx / TiO2 selectivity and resistance to SO2 toxicity. Fourier transform infrared spectroscopy showed that, unlike Fe2O3, WO3 also provided some Lewis acid active sites, indicating that Mn-W / TiO2 shows excellent catalytic activity for the selective reduction of NOx at low temperatures with the presence of low concentrations of SO2 .