改性 CeO 催化剂用于 NH 选择性催化还原 NO 中的酸度和氧化还原能力平衡。
The balance of acidity and redox capability over modified CeO catalyst for the selective catalytic reduction of NO with NH.
机构信息
Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
出版信息
J Environ Sci (China). 2019 May;79:273-279. doi: 10.1016/j.jes.2018.11.018. Epub 2018 Dec 13.
The effect of acidity and redox capability over sulfuric acid-modified CeO catalysts were studied for the selective catalytic reduction of NO with NH (NH-SCR). The deposition of sulfate significantly enhanced the catalytic performance over CeO. NO conversion over 4HSO/CeO at 230-440 °C was higher than 90%. The strong redox capability of CeO could result in unselective NH oxidation and decrease high temperatures catalytic activity and N selectivity. The deposition of sulfate increased the acidity and weakened the redox capability, and then increased the high temperature NO conversion and N selectivity. An appropriate level of acidity also promoted the activity at 190-250 °C over ceria-based catalysts, and with further increase in the acidity, the SCR activity decreased slightly. Weak redox capability lowered the low-temperature catalytic activity. Excellent SCR activity requires a balance of acidity and redox capability on the catalysts.
研究了酸性和氧化还原能力对硫酸改性 CeO 催化剂在 NH 选择性催化还原 NO（NH-SCR）反应中的影响。硫酸盐的沉积显著提高了 CeO 的催化性能。在 230-440°C 时，4HSO/CeO 的 NO 转化率高于 90%。CeO 的强氧化还原能力会导致 NH 的非选择性氧化，并降低高温下的催化活性和 N 的选择性。硫酸盐的沉积增加了酸性并减弱了氧化还原能力，从而提高了高温下的 NO 转化率和 N 的选择性。适当的酸度水平也促进了基于氧化铈的催化剂在 190-250°C 时的活性，而随着酸度的进一步增加，SCR 活性略有下降。弱氧化还原能力降低了低温催化活性。优异的 SCR 活性需要催化剂上的酸性和氧化还原能力达到平衡。
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