【作者】 陈小军；

【导师】 朱晓东； 喻强；

【作者基本信息】 成都大学 ， 材料与化工， 2024， 硕士

【摘要】 能源是人类社会发展的基石,随着化石资源的不断开发和利用,引发了能源短缺、气候变暖和环境污染等问题。为此推动传统化石能源结构的绿色转型,实现能源可持续发展,发展高效的绿色能源迫在眉睫。在新能源领域,直接甲酸盐燃料电池（DFFC）是一种新型的绿色能源转换装置,因其能量密度高、环保和安全性好等优点而备受瞩目。目前,DFFC阳极甲酸盐氧化反应（FOR）的最高效催化剂是Pd基催化剂。但是Pd基催化剂在FOR过程中存在H_ads中毒问题,即存在的强吸附中间体H_ads(Pd-H_ads)吸附在Pd表面,占据活性位点且难以剥离,这极大地削弱了FOR性能,限制了DFFC的发展和应用。因此在Pd表面实现H_ads的高效剥离和Pd的高效催化是本领域的研究重点。本文提出两种CuFe基催化剂(CuFe₂O₄/Fe₂O₃/CuO、Cu_xFe_12-x/Fe₂O₃/CuO)与Pd的协同氧化作用,加速H_ads从Pd催化剂活性位点剥离,这促使Pd的高效催化。本文主要的研究内容如下:（1）采用水热法合成了11种CuFe₂O₄/Fe₂O₃/CuO（CFO-x,x与Cu/Fe比相关）复合物,然后通过电沉积法将Pd负载到CFO-x表面,得到一系列Pd/CuFe₂O₄/Fe₂O₃/CuO（PCFO-x）复合催化剂。CFO-x具有良好的OH_ads生成能力,可以协同Pd加速对H_ads的氧化,减轻H_ads对Pd的毒害作用,从而提升催化剂的性能。结果表明,随着Cu/Fe比的增加,PCFO-x的FOR性能先增大后减小。优选后得到的PCFO-3（Pd/CuFe₂O₄）表现出4427 mA mg_Pd^-1的质量活性和243 mA cm^-2的比活性。由于PCFO-3的自适应特性,经过10000次CV循环后活性达到5649 mA mg_Pd^-1,且活性提高了27.6%。在12 h的长期I-t工作后,其剩余活性为26.95 mA mg_Pd^-1。（2）采用电沉积法设计和合成了一系列Pd/Cu_xFe_12-x/Fe₂O₃/CuO（PCF-x,x与Cu/Fe比相关）电催化剂,以提高FOR的活性和耐久性。亲氧性的Cu_xFe_12-x/Fe₂O₃/CuO（CF-x）作为协同催化剂具有良好的OH_ads生成能力,可以协同Pd活性位点H_ads的氧化,解决FOR过程中H_ads中毒的问题。沉积溶液中Cu/Fe阳离子比对催化性能起着至关重要的调节作用,随着Cu/Fe比的增加,PCF-x的FOR性能先增大后减小,优选后得到的PCF-4的性能最好。由于Pd与CF-4之间独特的协同作用,所制备的PCF-4催化剂具有优异的质量活性(6999 mA mg_Pd^-1)、比活性(385 mA cm^-2)、ECSA(87.4 m²g^-1)和CV循环耐久性（循环10000次后活性损失29.2%）。PCF-4工作12小时后剩余活性为36.72 mA mg_Pd^-1。更多还原

【Abstract】 Energy is the cornerstone of the development of human society,along with the perpetual development and use of fossil resources,some issues have been generated,such as energy shortage,climate warming and environmental pollution.Toward this end,promote the green transformation of the traditional fossil energy structure,and realize sustainable development of energy,the development of efficient and green energy is imminent.In the realm of new energy,direct formate fuel cell（DFFC）is one of new green energy conversion equipment,which has attracted much attention due to its merits of high energy density,friendly to environment and good safety.At present,the most effective catalyst for the formate oxidation reaction（FOR）of DFFC anode is Pd-based catalyst.However,the problem of H_ads poisoning exists in the FOR process of Pd-based catalyst,that is,the existing strong adsorption intermediate H_ads(Pd-H_ads)is adsorbed on the surface of Pd,occupying the active site and difficult to peel off,which greatly weakens the performance of FOR and limits the development and application of DFFC.Therefore,the research focus in this field is to achieve high efficiency stripping of H_ads and high efficiency catalysis of Pd on Pd surface.In this paper,two kinds of CuFe-based catalysts(CuFe₂O₄/Fe₂O₃/CuO,Cu_xFe_12-x/Fe₂O₃/CuO)were proposed to accelerate the stripping of H_adsfrom the active site of Pd catalyst by the synergistic oxidation with Pd,this promotes the efficient catalysis of Pd.The main research contents of this paper are as follows:（1）Eleven kinds of CuFe₂O₄/Fe₂O₃/CuO（CFO-x,x is related to Cu/Fe ratio）composites were synthesized by hydrothermal method,and then Pd were loaded onto the CFO-x surface by electrodeposition to obtain a series of Pd/CuFe₂O₄/Fe₂O₃/CuO（PCFO-x）composite catalysts.CFO-x had a good OH_ads generating ability,which could cooperate with Pd to accelerate the oxidation of H_ads and reduce the toxic effect H_ads on Pd,thus improve the performance of the catalsts.The results show that with the increase of Cu/Fe ratio,the FOR performance of PCFO-x first increased and then decreased.The optimized PCFO-3（Pd/CuFe₂O₄）exhibited a mass activity of 4427 mA mg_Pd^-1 and a specific activity of 243 mA cm^-2.Due to the adaptive properties of PCFO-3,the activity reached 5649 mA mg_Pd^-1 after 10000CV cycles and the activity increased by 27.6%.After 12 hours of long-term I-t work,its residual activity of 26.95 mA mg_Pd^-1（2）A series of Pd/Cu_xFe_12-x/Fe₂O₃/CuO（PCF-x,x is related to Cu/Fe ratio）electrocatalysts were designed and synthesized by electrodeposition to improve the activity and durability of FOR.Cu_xFe_12-x/Fe₂O₃/CuO（CF-x）with oxygen philic properties,as a co-catalyst,had a good OH_ads generating ability,which could coordinate the H_ads oxidation at the active site of Pd to solve the problem of H_ads poisoning during the FOR process.The cationic ratio of Cu/Fe in the deposited solution played an important role in regulating the catalytic performance.With the increase of Cu/Fe ratio,the FOR performance of PCF-x first increased and then decreased,and the optimized PCF-4 had the best performance.Due to the unique synergy between Pd and CF-4,the prepared PCF-4 catalyst showed excellent mass activity(6999 mA mg_Pd^-1),specific activity(385 mA cm^-2),ECSA(87.4 m² g^-1)and CV cycle durability（29.2%activity loss after 10000cycles）.The residual activity of PCF-4 was 36.72 mA mg_Pd^-1 after working for 12 hours.更多还原