Spatially Confined Assembly of Monodisperse Ruthenium Nanoclusters in a Hierarchically Ordered Carbon Electrode for Efficient Hydrogen Evolution

Abstract

The redox units of polyaniline (PAni)a re used cooperatively,a nd in situ, to assemble ruthenium (Ru) nanoclusters in ah ierarchically ordered carbon electrode.T he oxidized quinonoid imine (QI) units in PAni bond Ru complex ions selectively,w hereas reduced benzenoid amine (BA) units cannot. By electrochemically tuning the ratio of QI to BA,Ru complexes are spatially confined in the outer layer of hierarchical PAni frameworks.C arbonization of Ru-PAni hybrids induces nucleation on the outer surface of the carbon support, generating nearly monodisperse Ru nanoclusters.The optimizedcatalyst has alow loading of approximately 2wt% Ru, but exhibits am ass activity for the hydrogen evolution reaction that is about 6.8 times better than commercial 20 wt % Pt/C catalyst.

Modulating electronic structure of metal-organic frameworks by introducing atomically dispersed Ru for efficient hydrogen evolution

“…2b) can be clearly detected in NiRu 0.13 -BDC, further proving the successful doping of Ru. In addition, the Ru 3p peaks located at 462.9 and 485.5 eV were assigned to Ru 3+ 3p 3/2 and Ru 3+ 3p 1/2 , conforming the oxided state of Ru rather than metallic [51][52][53][54][55][56] . Meanwhile, there is a pair of peaks with an energy of 281.9 and 286.4 eV, which can be assigned to Ru 3d 5/2 and Ru 3d 3/2 in the C 1s and Ru 3d spectra ( Supplementary Fig.…”

“…Meanwhile, there is a pair of peaks with an energy of 281.9 and 286.4 eV, which can be assigned to Ru 3d 5/2 and Ru 3d 3/2 in the C 1s and Ru 3d spectra ( Supplementary Fig. 6) in comparision with Ni-BDC [51][52][53][54][55][56] , indicating the valance state of Ru 3+ and the successful incorporation of Ru single-atom into Ni-BDC. The remaining three peaks can be contributed to C=C bond at 284.8 eV, C-O bond at 285.8 eV and O-C=O bond at 288.8 eV 57 , in conformity with that of Ni-BDC.…”

“…6b), the Ru 3p peaks with binding energy of 463.4 and 485.8 eV were also result from the oxidized Ru. While, from Ru 3p of NiRu 0.21 -BDC, the peaks located at 461.7 and 484.3 eV for Ru 3p 3/2 and 3p 1/2 are assigned to metallic Ru, indicating the formation of Ru nanoparticles [51][52][53][54][55][56] . The Ni 2p spectra ( Fig.…”

Modulating Electronic Structure of Metal-Organic Frameworks by Introducing Atomically Dispersed Ru for Efficient Hydrogen Evolution

“…In addition, the Ru 3p peaks located at 462.9 and 485.5 eV were assigned to Ru 3+ 3p 3/2 and Ru 3+ 3p 1/2 , conforming the oxided state of Ru rather than metallic. [51][52][53][54][55][56] Meanwhile, there is a pair of peaks with an energy of 281.9 and 286.4 eV, which can be assigned to Ru 3d 5/2 and Ru 3d 3/2 in the C 1 s and Ru 3d spectra ( Supplementary Fig. 4) in comparision with Ni-BDC, [51][52][53][54][55][56] indicating the valance state of Ru 3+ and the successful incorporation of Ru single-atom into Ni-BDC.…”

“…4b), the peaks located at 461.7 and 484.3 eV for Ru 3p 3/2 and 3p 1/2 are assigned to metallic Ru, indicating the formation of Ru nanoparticles in NiRu 0.21 -BDC. [51][52][53][54][55][56] The local electronic structure and coordination environment of Ru in NiRu 0.13 -BDC were further investigated by X-ray absorption measurements. Figure 3a and Supplementary Fig.…”