A PdMn bimetallene for low-energy electrocatalytic hydrogen generation coupled with formate oxidation

Abstract

In this communication, PdMn bimetallene is synthesized by template-free solvothermal method under the assistance of diamines. PdMn bimetallene with rich defects and highly curved structures has superior performance for formate...

Regulation of the Work Function Difference Promotes In Situ Phase Transition of WO3–x for Efficient Formate Electrooxidation

“…The decreased intensity at 1.88 Å for Pd/WO 3– x -R implies high oxygen vacancy concentration, which is consistent with the EPR and PALS analyses. , Next, we tried to clarify the valence states of W, Pd, and O atoms in the catalysts by using X-ray photoelectron spectroscopy (XPS), as shown in Figures S6a,b and g. Figure S6a shows that the Pd 0 /(Pd 0 +Pd 2+ ) ratio of Pd/WO 3– x -R (47.2%) is higher than that of Pd/WO 3– x -P (42.9%), indicating that Pd/WO 3– x -R has more active sites to catalyze formate oxidation. , In comparison with Pd/WO 3– x -P (Pd 3d 5/2 and Pd 3d 3/2 binding energy at 334.96 and 340.34 eV), Pd/WO 3– x -R shows a slightly larger Pd 3d 5/2 and 3d 3/2 binding energy (335.40 and 340.65 eV), respectively, implying more charge transfer from Pd to WO 3– x in Pd/WO 3– x -R. , In addition, the O 1s spectrum of samples is shown in Figure S6b. The spectra of O 1s are made up of two peaks located at ∼530.4 and ∼531.3 eV, corresponding to the lattice oxygen and oxygen deficiency, respectively .…”

“…The onset potential is a crucial parameter for judging the performance of FOR. A low onset potential usually means a higher output voltage for DFFC Figure S7 exhibits the enlarged CV curves derived from Figure b,c, revealing the forward direction with a potential range of 0.05–0.65 V. As seen, Pd/WO 3– x -R shows an onset potential of 0.45, 0.46, and 0.49 V in 1, 2, and 5 M HCOOK solutions, respectively.…”

“…Figure S6a shows that the Pd 0 / (Pd 0 +Pd 2+ ) ratio of Pd/WO 3−x -R (47.2%) is higher than that of Pd/WO 3−x -P (42.9%), indicating that Pd/WO 3−x -R has more active sites to catalyze formate oxidation. 2,4 In comparison with Pd/WO 3−x -P (Pd 3d 5/2 and Pd 3d 3/2 binding energy at 334.96 and 340.34 eV), Pd/WO 3−x -R shows a slightly larger Pd 3d 5/2 and 3d 3/2 binding energy (335.40 and 340.65 eV), respectively, implying more charge transfer from Pd to WO 3−x in Pd/WO 3−x -R. 39,41 In addition, the O 1s spectrum of samples is shown in Figure S6b. The spectra of O 1s are made up of two peaks located at ∼530.4 and ∼531.3 eV, corresponding to the lattice oxygen and oxygen deficiency, respectively.…”

“…Excessive consumption of fossil fuels and serious environmental degradation have posed an urgent demand for clean, renewable energy technologies. In recent years, tremendous efforts have been devoted to developing direct formate fuel cells (DFFCs), and significant progress has been achieved in this field. , Especially, formate is an ideal fuel for direct alkaline fuel cells due to its easy production, non-toxicity, and environmental friendliness. , However, the performance of DFFCs is far below the practical demand, which is mainly caused by the slow kinetics of formate oxidation reaction (FOR) on anodic catalysts . Therefore, a grand challenge confronted by DFFCs is to develop efficient and robust electrocatalysts for FOR in alkaline electrolytes.…”

“…1,2 Especially, formate is an ideal fuel for direct alkaline fuel cells due to its easy production, non-toxicity, and environmental friendliness. 3,4 However, the performance of DFFCs is far below the practical demand, which is mainly caused by the slow kinetics of formate oxidation reaction (FOR) on anodic catalysts. 5 Therefore, a grand challenge confronted by DFFCs is to develop efficient and robust electrocatalysts for FOR in alkaline electrolytes.…”