Theoretical study of the oxidation of formic acid on a PtPd(111) surface

Abstract

By performing density functional theory calculations, the adsorption configurations of formic acid and possible reaction pathway for HCOOH oxidation on PtPd(111) surface are located. Results show that CO 2 is preferentially formed as the main product of the catalytic oxidation of formic acid. The formation of CO on the pure Pd surface could not possibly occur during formic acid decomposition on the PtPd(111) surface owing to the high reaction barrier. Therefore, no poisoning of catalyst would occur on the PtPd(111) surface. Our results indicate that the significantly increased catalytic activity of bimetallic PtPd catalyst towards HCOOH oxidation should be attributed to the reduction in poisoning by CO.

Polyvinyl alcohol‐modified graphene oxide as a support for bimetallic Pt–Pd electrocatalysts to enhance the efficiency of formic acid oxidation

“…Furthermore, the lattice parameter was calculated from the XRD peaks and was 0.225 nm, which is in between the values of Pt (0.226 nm) and Pd (0.224 nm). 6,12,13 The crystallite size was expanded from Scherrer line broadening analysis with the (111) diffraction peak of the XRD peak and was 11 nm, which is rather consistent with the TEM results.…”

“…Furthermore, the SAED patterns correspond to the (111) (200) (220) (222) (311) (331), (111) (200) (220) (311) and (111) (200) (220) (311) (420) crystal planes with face‐centered cubic (fcc) Pt, Pd and PtPd in the 6Pt/PVA/GO, 6Pd/PVA/GO, and 3Pt3Pd/PVA/GO catalysts, respectively. Generally, compared to the other planes, such as PtPd (200) and PtPd (220), the PtPd (111) plane is more stable for oxidation 13,37–40 . The HR‐TEM analysis of the sample is in Figure 2G.…”

“…The high peak currents (I b ) in the cathodic scan are principally due to the direct pathway at the clean catalyst surface without indirect oxidation. Formic acid oxidation occurs through dual pathways called direct and indirect pathways, as shown in Equations (11)(12)(13)(14). The addition of a second Pd metal to Pt is a significant way to expand catalyst activity.…”

“…The electrochemical evaluation suggests that the PtPd alloy electrocatalysts exhibit outstanding electrocatalytic activity toward formic acid oxidation in comparison with that of the Pt electrocatalyst. Moreover, Wang et al reported a theoretical study of formic acid oxidation on a single‐crystal PtPd (111) surface 13 . The CO adsorption energy on the PtPd (111) surface is lower than that on the Pd (111) surface, suggesting that CO desorption from PtPd (111) occurs more easily.…”

“…Moreover, Wang et al reported a theoretical study of formic acid oxidation on a singlecrystal PtPd (111) surface. 13 The CO adsorption energy on the PtPd (111) surface is lower than that on the Pd (111) surface, suggesting that CO desorption from PtPd (111) occurs more easily. The calculated results illustrate that formic acid oxidation to CO on the PtPd (111) plane becomes more complicated than that on the Pd (111) plane.…”