Reversing the charge transfer between platinum and sulfur-doped carbon support for electrocatalytic hydrogen evolution

Abstract

Metal–support interaction is of great significance for catalysis as it can induce charge transfer between metal and support, tame electronic structure of supported metals, impact adsorption energy of reaction intermediates, and eventually change the catalytic performance. Here, we report the metal size-dependent charge transfer reversal, that is, electrons transfer from platinum single atoms to sulfur-doped carbons and the carbon supports conversely donate electrons to Pt when their size is expanded to ~1.5 nm cluster. The electron-enriched Pt nanoclusters are far more active than electron-deficient Pt single atoms for catalyzing hydrogen evolution reaction, exhibiting only 11 mV overpotential at 10 mA cm−2 and a high mass activity of 26.1 A mg−1 at 20 mV, which is 38 times greater than that of commercial Pt/C. Our work manifests that the manipulation of metal size-dependent charge transfer between metal and support opens new avenues for developing high-active catalysts.

Platinum Atoms and Nanoparticles Embedded Porous Carbons for Hydrogen Evolution Reaction

“…In order to testify the catalytic activity derived from Pt species, Pt-free sample was prepared from the pyrolysis of porphyrin-based CMP (PC-N4-600), and then the HER activity was tested ( Figure S9), suggesting the essential of Pt to achieve high performance of PC-PtN4-600. Tafel slope is an efficient way to investigate the intrinsic reaction kinetics of the catalysts for HER [57,58]. As shown in Figure 5b, PC-PtN4-600 displays a Tafel slope of 42 mV dec −1 , which is very similar to that of Pt/C (43 mV dec −1 ), implying both of them share the same rate-determining step, where two hydrogen intermediates desorb and form H 2 molecule (Tafel step).…”

“…Although the overpotential increased with the reduced content of PC-PtN4-600, but the mass activity of the catalyst was enhanced. The stability performance of PC-PtN4-600 was first studied by the accelerated degradation test (ADT) [57]. Typically, PC-PtN4-600 was sprayed on carbon paper and then the CV measurements was performed in N 2 -saturated 0.5 M H 2 SO 4 electrolyte for 10,000 cycles between −0.15 to +0.15 V (vs. RHE).…”

Coordination engineering of iridium nanocluster bifunctional electrocatalyst for highly efficient and pH-universal overall water splitting

“…27) shows obvious electron transfer from Ir sites to the adjacent N and S atoms, indicating that Ir atom is positively charged with an average Bader charge of 0.22 in Ir 13 @NSG. Thus, compared with metallic Pt, the H adsorption/desorption on surficial Ir active sites of Ir-NSG can be balanced by the coordinated N and S atoms via electronic modulation 47,48 . The phenomenon of oxygen pre-adsorption on non-oxide active sites during OER has been reported and is evidenced by operando EXAFS spectroscopy in Fig.…”

Size effects of platinum particles@CNT on HER and ORR performance

“…With the Pt particle size decreasing, the proportion of the low-coordinated surface sites (corner or edge) increases, which leads to enhanced catalytic activity [16]. Yan et al [17] investigated the size effect of Pt nanoparticles supported on S-doped carbon material on HER, and found that~1.5 nm Pt clusters had better HER activity than Pt single atoms, indicating the electron transfer played an important role in HER. Garlyyev et al [18] studied the effect of different Pt particle sizes on ORR activity by using a metal-organic framework (MOF) to regulate the particle size, and pointed out that Pt particles with size of 1.1 nm exhibited better ORR activity.…”