Wang Chenxing, Mo Jiahui, Wang Haoting, Liu Jia, He Gege, He Xinhai, Song Yanyan
School of Materials Science and Engineering, Xi'an Key Laboratory of Textile Composites, Xi'an Polytechnic University, Xi'an 710048, China.
Nanomaterials (Basel). 2025 Feb 22;15(5):338. doi: 10.3390/nano15050338.
To enhance the electrocatalytic performance of a flexible Pd@CFs catalyst for methanol oxidation, deep cryogenic treatment in liquid nitrogen was introduced. The effects of the frequency and time of the deep cryogenic treatment on the surface crystal orientation, microstructure morphology, mechanical performance, and electrocatalytic performance for methanol oxidation were studied. The results showed that when the frequency of the deep cryogenic treatment was 2 times and the deep cryogenic time was 24 h, the electrocatalytic performance of the catalyst was the best. Compared with the catalyst without deep cryogenic treatment, the activity and stability of the catalyst increased by about 33% and 41%, respectively. The activity and stability of the catalyst were about 43.4 times and 6.3 times that of the commercial Pd/C catalyst, respectively. After 500 cycles of CV testing, the performance of the catalyst decay rate was only 3.9%. Compared to the CFs, the tensile strength and the elongation rates of the catalyst increased by 24.6% and 57%, respectively. This is due to deep cryogenic treatment causing Pd grains to rotate from a disordered arrangement to an ordered arrangement, making the metal particles more dispersed and exposing more active sites, ultimately improving the electrocatalytic oxidation ability of methanol. The excellent electrocatalytic efficiency of Pd@CFs-24-2 coupled with its simple and easy preparation method has great potential for promoting the development of DMFCs.
为提高柔性Pd@CFs催化剂对甲醇氧化的电催化性能，引入了液氮深低温处理。研究了深低温处理的频率和时间对表面晶体取向、微观结构形态、力学性能以及甲醇氧化电催化性能的影响。结果表明，当深低温处理频率为2次且深低温时间为24 h时，催化剂的电催化性能最佳。与未进行深低温处理的催化剂相比，该催化剂的活性和稳定性分别提高了约33%和41%。该催化剂的活性和稳定性分别约为商业Pd/C催化剂的43.4倍和6.3倍。经过500次循环伏安测试后，催化剂的性能衰减率仅为3.9%。与CFs相比，该催化剂的拉伸强度和伸长率分别提高了24.6%和57%。这是由于深低温处理使Pd晶粒从无序排列转变为有序排列，使金属颗粒更加分散并暴露出更多活性位点，最终提高了甲醇的电催化氧化能力。Pd@CFs-24-2优异的电催化效率及其简单易制备的方法对推动直接甲醇燃料电池（DMFCs）的发展具有巨大潜力。
