Search

The catalytic activity of metal clusters is closely related with the support; however, knowledge on the influence of the support on the catalytic activity is scarce. We demonstrate that Pt nanoclusters (NCs) anchored on porous TiO2 nanosheets with rich oxygen vacancies (VO‐rich Pt/TiO2) and deficient oxygen vacancies (VO‐deficient Pt/TiO2), display significantly different catalytic activity for the hydrogen evolution reaction (HER), in which VO‐rich Pt/TiO2 shows a mass activity of 45.28 A mgPt−1 at −0.1 V vs. RHE, which is 16.7 and 58.8 times higher than those of VO‐deficient Pt/TiO2 and commercial Pt/C, respectively. DFT calculations and in situ Raman spectra suggest that porous TiO2 with rich oxygen vacancies can simultaneously achieve reversed charge transfer (electrons transfer from TiO2 to Pt NCs) and enhanced hydrogen spillover from Pt NCs to the TiO2 support, which leads to electron‐rich Pt NCs being amenable to proton reduction of absorbed H*, as well as the acceleration of hydrogen desorption at Pt catalytic sites—both promoting the HER. Our work provides a new strategy for rational design of highly efficient HER catalysts. [ABSTRACT FROM AUTHOR]

Abstract: Two Pt single‐atom catalysts (SACs) of Pt‐GDY1 and Pt‐GDY2 were prepared on graphdiyne (GDY)supports. The isolated Pt atoms are dispersed on GDY through the coordination interactions between Pt atoms and alkynyl C atoms in GDY, with the formation of five‐coordinated C1‐Pt‐Cl4 species in Pt‐GDY1 and four‐coordinated C2‐Pt‐Cl2 species in Pt‐GDY2. Pt‐GDY2 shows exceptionally high catalytic activity for the hydrogen evolution reaction (HER), with a mass activity up to 3.3 and 26.9 times more active than Pt‐GDY1 and the state‐of‐the‐art commercial Pt/C catalysts, respectively. Pt‐GDY2 possesses higher total unoccupied density of states of Pt 5d orbital and close to zero value of Gibbs free energy of the hydrogen adsorption (|Δ G Pt H * |) at the Pt active sites, which are responsible for its excellent catalytic performance. This work can help better understand the structure–catalytic activity relationship in Pt SACs. [ABSTRACT FROM AUTHOR]

Dual-atom catalysts (DACs) have drawn much attention recently by virtue of the synergistic effect within the dual-atom sites, while controlled synthesis of pure DACs remains a challenge. Herein, a uniform dual-atom Ni 2 catalyst (Ni 2 -NCNT) was controllably synthesized using a dinuclear Ni complex as the precursor, in which directly bonded Ni 2 pairs are uniformly anchored on N-doped carbon nanotubes. Ni 2 -NCNT exhibits extraordinary catalytic activity, selectivity and stability for electroreduction of CO 2 into CO, with a partial current density for CO (j CO) of 76 mA cm–2. The j CO mass activity of Ni 2 -NCNT is 2.3-times higher than that of corresponding Ni 1 -NCNT single-atom catalyst. DFT calculations reveal that the synergistic coordination of *COOH at the Ni 2 dual-atom site can dramatically lower the reaction free energy for *COOH formation, thus promoting the CO 2 electroreduction. [Display omitted] • A strategy for controlled synthesis of pure dual-atom and single-atom catalysts. • The conditions for controlled synthesis of dual-atom catalyst were investigated in detail. • The j CO of dual-atom catalyst is 2.3-times higher than that of corresponding single-atom catalyst for CO 2 eledctroreduction. [ABSTRACT FROM AUTHOR]