Luo Guoming, Hu Shuozhen, Niu Dongfang, Sun Shigang, Zhang Xinsheng
State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
Nanoscale. 2022 Apr 21;14(16):6007-6020. doi: 10.1039/d1nr05777d.
Pd-Based catalysts are considered the most efficient catalysts in direct formic acid fuel cells. However, the poisoning and dissolution of Pd in acidic systems limit its commercialization. Here, we propose an all-in-one solution for the anti-dissolution and anti-poisoning properties of palladium. A novel structured catalyst, Pd nanoparticles embedded in a carbon layer internally decorated with tourmaline nanoparticles (TNPs), is proposed for formic acid oxidation (FAO). The internal electric field strength of the catalysts is readily regulated by controlling the amount of TNPs. Remarkably, the prepared catalyst exhibits as high as 3.9 times mass activity (905 A g) compared with the commercial Pd/C catalyst. The significant improvement in the electrocatalytic performance of the catalyst is mainly due to the polarized electric field of TNPs causing charge transfer from Pd to tourmaline, which weakens the O-H bond of HCOOH and the bond between Pd and CO. Another advantage brought by the internal polarized electric field is that it facilitates water dissociation to produce OH, thereby improving the anti-poisoning ability of the catalyst in acidic media. Moreover, the firmly anchored Pd nanoparticles can avoid dissolution and agglomeration during long-term use. 80.2% mass activity remained after the accelerated durability test.
钯基催化剂被认为是直接甲酸燃料电池中效率最高的催化剂。然而，钯在酸性体系中的中毒和溶解限制了其商业化应用。在此，我们提出了一种针对钯的抗溶解和抗中毒性能的一体化解决方案。我们提出了一种新型结构的催化剂，即嵌入碳层且内部装饰有电气石纳米颗粒（TNPs）的钯纳米颗粒，用于甲酸氧化（FAO）。通过控制TNPs的量，可以很容易地调节催化剂的内部电场强度。值得注意的是，与商业钯碳催化剂相比，制备的催化剂表现出高达3.9倍的质量活性（905 A g）。催化剂电催化性能的显著提高主要是由于TNPs的极化电场导致电荷从钯转移到电气石，这削弱了HCOOH的O-H键以及钯与CO之间的键。内部极化电场带来的另一个优势是它促进了水的解离以产生OH，从而提高了催化剂在酸性介质中的抗中毒能力。此外，牢固锚定的钯纳米颗粒可以避免在长期使用过程中的溶解和团聚。在加速耐久性测试后，仍保留80.2%的质量活性。
