Ultrathin Nanosheet of Graphdiyne-Supported Palladium Atom Catalyst for Efficient Hydrogen Production

Abstract

SummaryAtomic catalysts are promising alternatives to bulk catalysts for the hydrogen evolution reaction (HER), because of their high atomic efficiencies, catalytic activities, and selectivities. Here, we report the ultrathin nanosheet of graphdiyne (GDY)-supported zero-valent palladium atoms and its direct application as a three-dimensional flexible hydrogen-evolving cathode. Our theoretical and experimental findings verified the successful anchoring of Pd0 to GDY and the excellent catalytic performance of Pd0/GDY. At a very low mass loading (0.2%: 1/100 of the 20 wt % Pt/C), Pd0/GDY required only 55 mV to reach 10 mA cm−2 (smaller than 20 wt % Pt/C); it showed larger mass activity (61.5 A mgmetal−1) and turnover frequency (16.7 s−1) than 20 wt % Pt/C and long-term stability during 72 hr of continuous electrolysis. The unusual electrocatalytic properties of Pd0/GDY originate from its unique and precise structure and valence state, resulting in reliable performance as an HER catalyst.

Atomic Pd on Graphdiyne/Graphene Heterostructure as Efficient Catalyst for Aromatic Nitroreduction

“…Pd 1 /GDY/G, Pd 1 /GDY/G‐1, and Pd 1 /GDY/G‐2 with 0.855, 0.151, and 0.272 wt% Pd were prepared, respectively. The content of Pd in Pd 1 /GDY/G is about fourfold higher than previously reported Pd SAC supported by GDY nanosheets . Pd 1 /GDY/G exhibits excellent catalytic activity and high turnover frequency (TOF, defined here as the amount of reactant that is converted into product per min by 1 mmol of Pd) compared with previously reported Pd‐based catalysts, including the Pd SAC.…”

“…The valence states of Pd/GDY/G‐O and Pd 1 /GDY/G were investigated by XPS (Figure S17, Supporting Information). As shown in Figure e, the peaks of Pd 3d 5/2 and 3d 3/2 in Pd 1 /GDY/G shift to lower binding energy (335.2 and 340.8 eV) compared to those of Pd 1 /GDY/G‐O (337.4 and 342.7 eV), indicating the formation of zero‐valent palladium (Pd 0 ) complexes . The atomic‐resolution HAADF‐STEM image of Pd 1 /GDY/G illustrated that Pd atoms on the Pd 1 /GDY/G still maintain atomically dispersion without presence of any visible clusters or nanoparticles (NPs) (Figure S18, Supporting Information).…”

“…Graphdiyne (GDY) is a 2D carbon material that only consists of sp and sp 2 hybridized carbon atoms with diacetylenic linkages (CCCC) connecting adjacent benzene rings . Recently, SACs that anchor single atoms on GDY through the strong d–π interaction between metal atoms and carbon–carbon triple bonds have aroused great interest . The unique alkyne‐rich structure not only endows GDY with many attractive properties, but also makes GDY an ideal support for SACs because of the uniformly distributed pores and large binding energies to metal atoms .…”

“…Apart from the strong bonding or coordination between single atoms and the underlying supports, the high specific surface area (SSA) and conductivity of supports are essential factors for the enhancement of catalytic performance. Almost all the reported GDY‐supported SACs used 3D GDY nanowall/sheets with thickness about dozens of nanometers, but only the surface of GDY could provide anchoring sites for metal atoms . In order to maximize the anchoring sites in GDY, the SSA has to be increased by reducing the layer numbers of GDY.…”

Graphdiyne: A Rising Star of Electrocatalyst Support for Energy Conversion

“…Very recently, Xue's group successfully stabilized zero‐valence palladium atoms (Pd 0 ) on GDY surface through electrochemical deposition, which displayed superior HER performance. [ 113 ] The authors investigated the critical mechanism of superior HER performance through their proposed two‐way crossover linear response technique. [ 114 ] The result showed that both singly and triply symmetrically fixed Pd atoms held the closed shell (crossover) effect, which manifested the formidable orbital overlaps between Pd atoms and adjacent C atoms.…”