HYBRID MATERIAL BASED ON SULPHUR-DOPED GRAPHENES WITH REDUCED PLATINUM CONTENT, EFFECTIVE IN OXIDATION REACTION OF METHANOL IN ALKALINE MEDIUM

摘要

The invention relates to a hybrid material based on reduced sulphur-doped graphene oxide with reduced platinum content of 2%, meant to be used as an anode in fuel cells with direct methanol supply in alkaline medium, and to a process for preparing the same. According to the invention, the material comprises the following elements, as weight percentage: 80.55% carbon, 1.26% hydrogen, 14.47% oxygen, 1.72% sulphur and 2% platinum, the material exhibiting reproducibility, stability and high catalytic activity in methanol oxidation reaction in alkaline medium. According to the invention, the process has two stages: 1. preparing the sulphur-doped graphene oxide S-RGO with ultrasonic dispersion of 100 mg of graphene oxide in 100 ml of ethylene glycol for one hour, ultrasonic dispersion of 160 mg of sodium sulphide in the graphene oxide/ethylene glycol suspension for 45 min, autoclaving the resulting suspension for 12 h at a temperature of 180°C, followed by processing the resulting product by filtration, washing and lyophilization, and 2. decorating the S-RGO product prepared during the first stage with platinum nano-particles while dispersing 50 mg of S-RGO in 32 ml of ethylene glycol for one hour by ultrasonication, adjusting the pH to 10.5 with NaOH 1M, dispersing 112 μ l of hexachloroplatinum acid 0.095 M in the S-RGO/ethylene glycol suspension for 10 min by ultrasonication, autoclaving the suspension obtained thereby for 8 hours, at a temperature of 180°C and, finally, processing the resulting product S-RGO-Pt by filtration, washing and lyophilization.