Pd-Cu@UiO-66催化还原水中硝酸盐

为解决地下水中硝酸盐含量过高的问题,首次制备了双金属Pd-Cu@UiO-66催化剂用于催化还原水中硝酸盐的研究,重点考察了不同调节剂制备的载体和工艺条件对脱硝性能的影响。结果表明:采用盐酸制备的UiO-66载体,Pd、Cu金属负载量分别为1%,氢气流量为70 mL/min时,硝酸盐脱除率为97.4%,N₂的选择性可达到95.2%。pKa值越低的调节剂所制备的载体粒径越小,越有利于活性金属的分散,且形成的金属粒径较小。活性金属的高度分散有利于活化氢的生成及Cu的电子迁移,能够提高脱硝反应中N₂的选择性。在反应过程中,双金属的协同效应是影响催化性能的关键因素。

CATALYTIC REDUCTION OF NITRATE IN WATER BY Pd-Cu@UiO-66

To solve the problem of high nitrate content of groundwater, bimetal Pd-Cu@UiO-66 catalyst was prepared for the catalytic reduction of nitrate in water for the first time. The influence of the carrier synthesized with different regulator and process conditions on denitrification performance was investigated. The results showed that the nitrate removal rate was 97.4%, and N₂ selectivity was 95.2% when the UIO-66 carrier was prepared by hydrochloric acid with the loading of 1% Pd and 1% Cu and the hydrogen flow rate was 70 mL/min. The carrier prepared with the modulator of lower pKa had the smaller particle size, which was conducive to the formation and dispersion of smaller active metal particles. The high dispersion of active metal was beneficial to the generation of activated hydrogen and the electron transport of Cu, and to improve the selectivity of nitrogen in denitration reaction. During the reaction, the bimetallic synergic effect was the key factor affecting the catalytic performance.