In situ synthesis of well crystallized rhodium sulfide/carbon composite nanospheres as catalyst for hydrochloric acid electrolysis

Abstract

Rhodium sulfide/carbon nanocomposites were synthesized via a one-step alcohol-thermal method at 400 C from Rh 6 (CO) 16 and elemental S. Characterizations by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy revealed that the products were composed of amorphous carbon with spherical morphology and numerous highly crystallized Rh 2 S 3 /Rh 17 S 15 nanocrystals, presented as uniform size composite nanospheres of 45-90 nm diameter. The crystallographic composition of rhodium sulfide in those composites depended on the initial S/Rh molar ratio and utilized solvent. Such hybrid nanomaterials displayed good dispersion of the rhodium sulfide nanoparticles, high surface area and extraordinary thermal/chemical resistance, making them attractive materials for electrocatalytic application of HCl electrolysis. Cyclic voltammetry and rotating disk electrode measurements were employed to evaluate the catalytic performance for oxygen reduction reaction in HCl electrolysis. It was illustrated that all rhodium sulfide/carbon nanocomposites were active towards oxygen reduction reaction. Especially, the catalyst synthesized in ethanol containing Rh 17 S 15 phase outperformed commercial Pt/C in stability. Recently, our group reported hydrothermal and xylenethermal synthesis of rhodium suldes. 24,25 Both methods led to well-crystallized Rh 2 S 3 or Rh 17 S 15 phase, depending on the initial S/Rh molar ratio in the raw materials. The solvothermal reaction conducted in xylene gives rise to products with higher

Nanocrystal engineering of noble metals and metal chalcogenides: controlling the morphology, composition and crystallinity

“…13e), high surface area and This journal is © The Royal Society of Chemistry 2015 extraordinary thermal/chemical resistance, making them candidate materials for electrocatalytic application of HCl electrolysis. 278 Additionally, Rao and colleagues published a 'Frontiers article' on the structural and spectroscopic features of MoS 2 nanosheets, as well as on their impressive properties. MoS 2 typifies the family of metal dichalcogenides such as MoSe 2 and WS 2 and there's much to be done on nanosheets of these materials.…”

Rh2S3/N‐Doped Carbon Hybrids as pH‐Universal Bifunctional Electrocatalysts for Energy‐Saving Hydrogen Evolution

“…The fine-scanned Rh 3d XPS spectrum was given in Figure S1a of the Supporting Information, in which peaks of 313.4 and 308.7 eV were assigned as Rh 3d 3/2 and Rh 3d 5/2 , respectively, indicating the existence of Rh 3+ and RhS bonds. [24,25] As shown in Figure S1b of the Supporting Information, the high-resolution S 2p XPS spectrum could be fitted to two main peaks, relating 162.3 and 163.5 eV to S 2p 3/2 and S 2p 1/2 peaks, respectively, also demonstrating the presence of RhS bonds. [26,27] Apparently, no signs of oxidized S (e.g., sulfonates) were detected as no peaks were observed at 168.0 eV.…”

Pyridine‐Stabilized Rhodium Nanoparticles in Ionic Liquids as Selective Hydrogenation and Transfer Hydrogenation Catalysts

“…XPS spectra were fitted with the program CasaXPS . The assignment of chemical components of core level N 1s and Rh 3d were made using the referenced value reported in the literature , …”