Low-temperature N-anchored ordered Pt₃Co intermetallic nanoparticles as electrocatalysts for methanol oxidation reaction

Abstract

To enhance nanocatalyst performance and durability for the methanol oxidation reaction (MOR) in direct methanol fuel cell, small-sized (2.1 nm) and structurally ordered Pt3Co intermetallic is uniformly anchored onto nitrogen-doped...

Highly Dispersed PdNi Nanoparticles on an Oxygen-Functionalized Activated Carbon with Extraordinary Electrocatalytic Activity for Methanol Oxidation

“…The stability of catalysts was examined by chronoamperometry (CA) tests in 1.0 mol/L KOH + 1.0 mol/L CH 3 OH at −0.2 V. It can be seen from Figures b and S2b, the current density generated by catalysts with different compositions during the methanol oxidation process declines rapidly at the initial stage and then tends to stabilize over time, which is related to the adsorption–desorption equilibrium of methanol and intermediates produced by oxidation on the catalyst surface. − Within 3600 s, the electrochemical activity of Pd 4 Ni 1 /FAC was still higher than that of other alloy samples. In contrast, the current density of Pd 4 Ni 1 /AC decreases more quickly than that of Pd 4 Ni 1 /FAC, indicating that the oxygen-containing groups on the activated carbon surface may be beneficial to the removal of CO ads generated during the methanol oxidation.…”

Intermetallic Nanocrystals for Fuel-Cells-Based Electrocatalysis

“…One of the advantages that intermetallic catalysts have over their alloy counterparts lie in their enhanced capacity to influence the d -band/electronic structure. ,,, Despite various attractive shapes that have been realized on alloy nanocrystals, the developments of nanomaterial fabrication techniques also contributes to more and more fancy intermetallic compounds with increasingly smaller average sizes, ,,,,,− much more complicated composition, ,,,,− and tailored nanoscale morphology ,,,,− (as discussed in section and ). In contrast to the rather random atomic arrangement in disordered alloy structure, alternated distribution in intermetallics realizes sufficient interaction between different atomic species.…”

“…This P-vacancies-induced-phase-transition was also a general strategy to prepare L1 0 -PtNi and PtFe intermetallic nanoparticles. Apart from the P atoms, N-doping is also beneficial for accelerating the formation of PtCo and PtNi intermetallics by leaving the corresponding vacancies. − The diffusion of these anions have significantly lowered the disorder-to-order phase transition temperature of intermetallics.…”

Insights on the Roles of Nitrogen Configuration in Enhancing the Performance of Electrocatalytic Methanol Oxidation over Pt Nanoparticles

“…[28] Furthermore, the adsorption energy of CH 3 OH on the active sites of different models also supports this conclusion (Figure 1k; Table S1, Supporting Information), i.e., the synergistic effect between pyrrolic-N and Pt can enhance the adsorption of CH 3 OH at the site of Pt, thus providing sufficient CH 3 OH * for the subsequent reaction. Based on the Gibbs free energy calculations for all the basic steps in the sequential dehydrogenation process in our previous work, [22] it is known that the activation energy barrier of CO * ─CO * +OH * , which is the ratelimiting step (RLS) of MOR on Pt (111) surface, may reflect the CO tolerance of the catalyst. [22] Notably, the Pt/pyridinic-N-CNTs have a lower activation energy barrier compared with other models (Figure 1l; Figure S2, Supporting Information), which is more thermodynamically favorable.…”