以Cu?TEPA为模板剂原位水热合成一系列具有优良deNOx特性的Cu?SSZ?13／堇青石整体式催化剂．为进一步改善其氨的选择性催化还原氮氧化物的活性，在制备过程中添加HF对原位制备Cu?SSZ?13／堇青石整体式催化剂进行改性．利用XRD、SEM、XPS、BET、ICP?AES等对样品进行了表征．结果表明，当 nHF／nAl在0?015—0．0375时，晶化72 h的Cu?SSZ?13／堇青石表现出了优异的脱硝性能和抗老化性能，其最大转化率为99．8％，NOx转化率保持在90％以上的最宽活性温度窗口为280—640℃，而无HF的新鲜样品的NOx转化率保持在90％以上的活性温度窗口为300—580℃；720℃老化50 h处理后，nHF／nAl＝0．015—0．0375样品的NOx转化率保持在90％以上的最宽活性温度窗口为360—520℃，未添加HF的老化样品相应的活性温度窗口为400—500℃．无论新鲜还是老化，nHF／nAl＝0．015—0．0375样品在低温段200—300℃和高温段500—700℃的NOx转化率基本都大于未添加HF的样品．结合表征结果，在催化剂原位水热合成过程中HF的加入既提高了样品的相对结晶度和负载量，又增大了样品的比表面积和比孔容，且提高了Cu?SSZ?13／堇青石骨架结构的稳定性，进而在一定程度上改善了Cu?SSZ?13／堇青石的高温脱硝活性和水热稳定性．
A series of Cu?SSZ? 13/cordierite catalysts that had excellent deNOx activity were successfully synthesized by the in situ hydrothermal method with Cu?TEPA as the template agent. In order to further improve the activity of the selective catalytic reduction ( SCR) of NOx with ammonia, HF with different dosage was added into the initial jel during the preparation of Cu?SSZ?13/cordierite. The physicochemical properties of the samples were characterized by X?ray diffraction ( XRD ) , scanning electron microscopy ( SEM ) , X?ray photoelectron spectroscopy ( XPS ) , inductively coupled plasma?auger electron spectroscopy ( ICP?AES) and N2 adsorption techniques. When the nHF/nAl mole ratio ranged from 0. 015 to 0. 0375, Cu?SSZ?13/cordierite with 72 h crystallization time showed excellent catalytic activity and anti?aging ability, with the maximum NOx conversion rate up to 99.8%. The widest activity temperature window at NOx conversion rate >90%was 280—640 ℃ while that of sample without HF was 300—580 ℃. After hydrothermal aging treatment at 720 ℃ for 50 h, the widest activity temperature window ( NOx conversion rate >90%) was 360—520 ℃ while that of sample without HF was 400—500 ℃. Whether fresh or aged samples, at the low temperatures (200—300 ℃) and high temperatures (500—700 ℃), the NOx conversion rate of nHF/nAl= 0?015—0.0375 samples was mostly greater than that of samples without HF. The characterization results indicated the addition of HF improved the relative crystallinity, loading amount, the specific surface area and pore volume, even enhanced the stability of the framework structure of Cu?SSZ?13/cordierite, thus improving the deNOx reduction rate at high temperatures and hydrothermal stability to a certain extent.
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