文献类型：期刊文献

中文题名：高性能Pd/ZrO_(2)催化剂制备及甲烷燃烧性能的研究

英文题名：Preparation of High-Performance Pd/ZrO_(2)Catalyst for Methane Combustion

作者：唐璇[1];唐冰静[1];刘营[2];郭杨龙[1];谷启源[2];苗晓刚[2];詹望成[1];王丽[1];郭耘[1]

机构：[1]华东理工大学化学与分子工程学院工业催化研究所,上海200327;[2]有研资源环境技术研究院(北京)有限公司,北京101407

年份：2025

卷号：49

期号：8

起止页码：1200

中文期刊名：稀有金属

外文期刊名：Chinese Journal of Rare Metals

收录：;EI(收录号：20262721043669);北大核心:【北大核心2023】；

基金：国家自然科学基金项目(U21A20326)资助。

语种：中文

中文关键词：钯Pd;甲烷(CH_(4))燃烧;催化剂;高性能

外文关键词：palladium;methane combustion;catalyst;high performance

摘要：本文通过改变ZrO_(2)载体的制备条件及负载金属的方法来调节Pd/ZrO_(2)催化剂的甲烷催化燃烧性能。结合高角环形暗场像扫描透射电子显微镜(HAADF-STEM)、CO脉冲、氢气程序升温还原(H_(2)-TPR)、氧气程序升温脱附(O_(2)-TPD)和X射线光电子能谱(XPS)表征,考察了制备方法的改变对于催化剂氧化还原性能和Pd物种化学状态的影响,发现沉积沉淀法制备的催化剂中Pd物种有着更高的价态和更好的分散性,具有更多的表面吸附氧,提高了催化剂吸附和活化氧的能力,从而有利于提高甲烷催化燃烧性能,优化后的催化剂的甲烷最低全转化温度低至347℃,同时具有良好的抗水性能。
Methane,as a primary component of natural gas,is widely used in power generation and heating applications.The emission of unburned methane causes air pollution and energy waste.Catalytic methane combustion is an effective and economical strategy to obtain high energy transforming efficiency and low emissions of toxic pollutants.Noble metal Pd-based catalysts are the most effective catalysts for methane combustion currently.The property of the support is one of the main factors affecting catalytic performance.Pd/ZrO_(2)catalyst has good hydrothermal stability but its methane combustion activity needs to be further improved.The methane catalytic combustion performance of the Pd/ZrO_(2)catalyst was enhanced by optimizing the preparation conditions of ZrO_(2)support and the preparation methods of catalysts in this work.X-ray diffraction(XRD)results showed that the preparation conditions would affect the crystal phase and grain size of the ZrO_(2).The grain size of ZrO_(2) gradually decreased with the increase of pH value and the decrease of calcination temperature.Meanwhile,with the increase in pH value,part of m-ZrO_(2)was gradually transformed into t-ZrO_(2),and the increase in temperature could make t-ZrO2 gradually transformed into m-ZrO2.The optimized catalytic performance and water-resistant of the Pd/ZrO_(2)catalyst for methane combustion could be obtained when the precipitation pH value was 12 and the calcination temperature was 700℃during the ZrO_(2)support preparation process.Two kinds of Pd/ZrO_(2)catalysts were then prepared by deposition precipitation(DP)method and incipient wetness impregnation(IM)method using ZrO_(2)which was synthesized under the optimized preparation conditions as the support.The Pd/ZrO_(2)catalysts prepared by the DP method showed better catalytic performance for methane combustion(the methane complete conversion temperature reached 347℃,and had good water resistance)than that of the Pd/ZrO_(2)catalysts prepared by the IM method(the methane complete conversion temperature was 378℃).The CO pulse experiments revealed that Pd/ZrO_(2)catalyst prepared by the DP method(Pd dispersion was 29%)had better dispersion of Pd species than that of the Pd/ZrO_(2)catalyst prepared by the IM method(Pd dispersion was 34%).High-angle annular dark field scanning transmission electron microscopy(HAADF-STEM)and corresponding energy dispersive spectrometer(EDS)-mapping images showed that some aggregated Pd species existed in both catalysts prepared by diferent methods but more abundant smaller size Pd species could be observed in Pd/ZrO_(2)catalysts prepared by the DP method,which was consistent with CO pulse experiments.The influence of the preparation method on the redox performance of the catalyst and the chemical state of the Pd species was investigated by combining with H,-temperature programmed reduction(H,-TPR),O-temperature programmed desorption(O_(2)-TPD),and X-ray photoelectron spectroscopy(XPS).XPS signals of Pd 3d indicated that the Pd species on Pd/ZrO_(2)catalyst prepared by DP method existed in a more electron-deficient oxidation state compared with the Pd/ZrO_(2)catalyst prepared by IM method.XPS signals of O s showed that there was more chemically adsorbed oxygen on the surface of the Pd/ZrO_(2)catalyst prepared by DP method,which had a stronger ability to adsorb and activate oxygen.H,-TPR results suggested that the introduction of Pd significantly changed the reduction performance of the catalyst,and the valence state of PdO,species in Pd/ZrO_(2)catalyst prepared by DP method was higher than that of Pd ZrO_(2)catalyst prepared by IM method,which was consistent with XPS results.O_(2)-TPD experiment further demonstrated this point.These results showed that the Pd species in the catalyst prepared by the DP method had more high valence state of Pd species and with more surface adsorbed oxygen which could improve the ability of the catalyst to adsorb and activate oxygen,which was beneficial to improve the catalytic performance for methane combustion.