Tailoring Reaction Pathways by Tuning the Surface Composition of AuPt Nanocatalysts for Enhanced Formic Acid Oxidation

Abstract

Pt-based nanocatalysts are universally applied in direct formic acid fuel cells. For Pt-based nanocatalysts, formic acid oxidation involves two pathways: dehydrogenation and dehydration. Dehydration, due to the production of CO, can poison the surface of the catalyst and thus reduce the catalytic efficiency. The tuning of the composition of Pt-based nanocrystals can effectively improve selectivity for dehydrogenation, especially for AuPt nanocrystals. However, it is still a challenge to tune the composition of AuPt nanocrystals in a nanometer size. Herein, we put forward a remarkably effortless technique for tailoring reaction pathways of formic acid oxidation by tuning the surface composition of AuPt nanocatalysts. Compared with the unmodified AuPt nanoparticles and commercial Pt/C nanocatalysts, the modified AuPt nanoparticles exhibit significantly enhanced catalytic properties. It shows a mass activity of 1.94 mA mg Pt −1 at 0.61 V versus the reversible hydrogen electrode, 19.4 times and 7.5 times higher than that of Pt/C nanocatalysts (0.1 mA mg Pt −1) and Pt-rich Au@Pt nanoparticles (0.26 mA mg Pt −1 ), respectively. Meanwhile, it also exhibits that the specific activity of modified AuPt nanoparticles is 7.89 mA cm −2 at 0.61 V, 46.4 times and 7.2 times higher than that of the Pt/C reference (0.17 mA cm −2 ) and Pt-rich Au@Pt nanoparticles (1.09 mA cm −2 ), respectively.

No Annealing Synthesis of Ordered Intermetallic PdCu Nanocatalysts for Boosting Formic Acid Oxidation

“…Direct formic acid fuel cells are regarded as one of the most promising energy conversion devices because they are environment-friendly clean energy. − It has lower overvoltage, lower toxicity, and higher safety performance . Compared with hydrogen fuels, formic acid fuels are easier to store and transport .…”

Precisely Tuning the Surface Nanostructure of Ni@Pd Nanocatalysts for Enhanced Formic Acid Oxidation

“…Generally, formic acid oxidation reaction has two reaction paths, dehydrogenation and dehydration process. [4,11,38] The dehydrogenation process takes place under the low electric potential and dehydration process requires a high potential. [4] Therefore, the reaction paths can be justified by the position of the peak of FAO.…”

“…[4,11,38] The dehydrogenation process takes place under the low electric potential and dehydration process requires a high potential. [4] Therefore, the reaction paths can be justified by the position of the peak of FAO. As shown in the Figure 4a, the formic acid oxidation peaks of the Ni@Pd nanoparticles locate at a low potential (around the 0.4 V).…”

“…Direct formic acid fuel cells (DFAFCs), which possess advantages of high power density, mild fuel crossover, and environment friendly, have received a lot of attention from scientists. [1][2][3][4][5][6][7] In the electrocatalytic oxidation reaction of formic acid (FAOR), the Pd-based nanocatalysts with the weak adsorption of carbon monoxide show higher catalytic activity than the Pt-based nanocatalysts. [8][9][10][11][12][13][14][15] However, Pd is a rare resource which severely limits its large-scale application in the real world.…”

Iron- and Cobalt-Doped Palladium/Carbon Nanoparticles as Catalysts for Formic Acid Oxidation

“…Relevant studies show that the electronic structure and composition of catalysts can be effectively tuned by doping other elements (H, B, P, S, Cr, Ga, Rh, Fe, and Co), greatly improving the catalytic efficiency of the catalysts. − In the catalytic reaction, the amount of doping metal greatly affects its catalytic efficiency . Usually, the optimum catalytic efficiency corresponds to the optimum composition of the catalyst . Hence, to obtain the best catalytic efficiency, it is necessary to carefully regulate the doping composition of a catalyst.…”