一步法合成不同Si/Al比的多级孔Cu/SAPO-34及其NH_(3)-SCR性能研究

One-step synthesis of hierarchical pore Cu/SAPO-34 with different Si/Al ratios and its NH_(3)-SCR properties

通过改变SiO_(2)的投料量,以柠檬酸铜为铜源、CaCO_(3)为硬模板,采用水热法一步合成不同Si/Al比的多级孔Cu/SAPO-34催化剂。制备的催化剂表现出优异的氨选择性还原脱硝性能。催化性能测试结果表明:Si/Al比为0.5的样品的活性温度窗口为180~420℃,同时还表现出了优异的水热稳定性和抗水抗硫性能,且相比于低Si/Al比的催化剂,Si/Al比高的催化剂能够表现出更好的水热稳定性。这是由于具有高含量的Si可更有效地保护骨架Al不受水蒸气的侵蚀而发生水解。

The hierarchical pore Cu/SAPO-34 catalysts with different Si/Al radios were synthesized by hydrothermal method by changing the amount of SiO_(2),using cupric citrate as the copper source and CaCO_(3) as the hard template.The prepared catalyst showed excellent performance of selective reduction of NOx by ammonia.The catalytic performance test results show that the Cu/SAPO-34 sample with Si/Al ratios of 0.5 has an activity temperature window of 180~420℃,and excellent hydrothermal stability and resistance to water and sulfur.Compared with catalysts with low Si/Al ratios,catalysts with high Si/Al ratios can show better hydrothermal stability,because the high content of Si can more effectively protect the skeleton Al from water vapor erosion,and hydrolysis occurs.