SAPO-34s with varying Si content templated by bulky tetraethylammonium hydroxide (TEAOH) were prepared to investigate the effect of Si environments on the selective catalytic reduction (SCR) of NO_x and the moisture stability of Cu-SAPO-34 catalysts. These Cu-SAPO-34s have similar Cu loadings, isolated Cu²⁺ content, and Brønsted acid sites (BAS). Both the ratio of Si islands and the acid strength of Cu-SAPO-34s increase with increasing Si content. In situ diffused reflection infrared Fourier transform spectroscopy (DRIFTS) studies reveal that the NH₃ adsorbed on mild BAS (associated with Si(4Al) species) is more active for NO_x conversion than NH₃ adsorbed on strong ones (associated with Si islands). This agrees well with the high turnover frequency (TOF) and the low activation energy on Cu-SAPO-34 with low Si content and abundant Si(4Al) species (sample Si-7.7). Upon hydration treatment, the textural properties, strong acid sites, and reducibility of isolated Cu²⁺ ions show a decrease. This deterioration intensifies with the increasing Si islands in the catalysts due to the easier occurrence of Si migration and the formation of larger Si islands. Sample Si-7.7 exhibits the best moisture stability and thus well-preserved denitration performance. These results imply that a practical Cu-SAPO-34 catalyst with superior activity and moisture stability may be achieved by controlling the Si environments of SAPO-34 templated by bulky amines.

制备具有改变由笨重氢氧化四乙铵（TEAOH）模板Si含量SAPO-34，调查硅环境对选择性催化还原（SCR）的NO的影响_X和Cu-SAPO-34的催化剂中的水分的稳定性。这些Cu-SAPO-34具有相似的Cu含量，分离的Cu ²⁺含量和布朗斯台德酸位（BAS）。随着Si含量的增加，Si岛的比例和Cu-SAPO-34s的酸强度均增加。原位漫反射傅里叶变换红外光谱（DRIFTS）的研究表明，该NH ₃吸附于温和BAS（有Si（4AL相关联的）物种）更活跃NO _X转化率比NH ₃吸附在坚固的硅片上（与硅岛相关）。这与具有低Si含量和大量Si（4Al）物种的Cu-SAPO-34的高周转频率（TOF）和低活化能非常吻合（样品Si-7.7）。水合处理后，孤立的Cu ²⁺离子的质构性质，强酸位和还原性降低。由于容易发生Si迁移和形成较大的Si岛，这种劣化随着催化剂中Si岛的增加而加剧。Si-7.7样品表现出最佳的水分稳定性，因此保留了良好的脱硝性能。这些结果表明，可以通过控制由笨重的胺模板化的SAPO-34的Si环境来获得具有优异的活性和水分稳定性的实用的Cu-SAPO-34催化剂。