Oxygen Electroreduction on Platinum Nanoparticles Deposited onto D-Glucose Derived Carbon

Abstract

Microporous-mesoporous carbon material synthesized from D-(+)-glucose using hydrothermal carbonization method was used as a porous support for platinum nanoparticles catalyst for oxygen electroreduction reaction (ORR). The platinum nanoparticles were deposited onto the support using sodium borohydride reduction method. The XRD, HRTEM, HRSEM, EDX, Raman spectroscopy and low-temperature N 2 adsorption/desorption techniques were used to characterize the structures of unmodified and Pt-nanoclusters modified materials. The carbon support with high specific surface area (1190 m 2 g −1 ) composes of almost ideally spherical amorphous microporous particles. The platinum nanoparticles are well dispersed on the surface of carbon particles. Cyclic voltammetry, rotating disc electrode and electrochemical impedance spectroscopy were applied to investigate the electrochemical behavior and ORR kinetics at the materials in 0.5 M H 2 SO 4 aqueous solution. The Pt-nanoclusters modified material has good ORR activity but on the non-modified carbon support the ORR is sluggish. Cyclic voltammetry and impedance data showed that unmodified and Pt-nanoclusters modified materials have noticeable double layer (≈ 200 F g −1 ) and faradaic capacitances (up to 250 F g −1 ).

Hydrothermal Carbonization‐Derived Carbon from Waste Biomass as Renewable Pt Support for Fuel Cell Applications: Role of Carbon Activation

“…While untreated hydrochars are reported to have very low surface areas below 100 m 2 g À1 , [16] which is consistent with the char from this study, activations of hydrochar are reported to increase specific surface areas. [26,[30][31][32] Here, the different activations led to an increase by a factor of 6 for physical and chemical activation and a factor of 7 for thermal activation. In other studies, areas after activation using KOH are, e.g., 2125 m 2 g À1 [24] and after activation using pyrolysis, e.g., 1190, [26] or 189 m 2 g À1 , [25] which strongly depends on processing parameters during activation and especially on the raw material for HTC.…”

“…[26,[30][31][32] Here, the different activations led to an increase by a factor of 6 for physical and chemical activation and a factor of 7 for thermal activation. In other studies, areas after activation using KOH are, e.g., 2125 m 2 g À1 [24] and after activation using pyrolysis, e.g., 1190, [26] or 189 m 2 g À1 , [25] which strongly depends on processing parameters during activation and especially on the raw material for HTC. Overall, BET analysis shows first that the porosity of each activated carbon from HTC is comparable to carbon black in terms of forming type II isotherms according to IUPAC classification and second that the specific surface areas of activated chars are much higher than the area of common carbon black.…”

“…[19][20][21][22] Moreover, hydrochars have shown potential for becoming a substitute for petroleum-based electrodes and catalyst support materials in applications such as supercapacitors [23,24] or fuel cells. [25,26] Therefore, physical, chemical, or thermal activations are reported in several studies to promote the carbonization of hydrochars and to increase the specific surface area. For example, Ledesma et al [27] added a controlled oxidizing gas stream into the autoclave and achieved a specific surface area of 320 m 2 g À1 .…”

“…[36] Thermal treatments of hydrochars at 800-900 C in different atmospheres were reported to result in an activated carbon with 1190 m 2 g À1 . [26] Pyrolysis of hydrochars at 900 C for 4 h in nitrogen atmosphere led to carbons with surfaces areas of 189-321 m 2 g À1 . [25] Carbon supports in Pt catalysts, for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFC), require a maximized surface area and a defective carbon surface for anchoring and distributing Pt nanoparticles, porosity for mass transport, and electrical conductivity to guarantee the electron transfer to catalytic active Pt sites.…”

“…Sevilla et al [42] used saccharides for HTC at 180-240 C followed by nickel nitrate impregnation and pyrolytic activation at 900 C. They used the activated carbons with 114-134 m 2 g À1 for the deposition of Pt nanoparticles and measured an ECSA of 67-85 m 2 g Pt À1 . In another study, Taleb et al [26] carried out HTC of D-glucose at 260 C for 24 h followed by thermal treatment at 800-900 C in different atmospheres to get carbon particles with 1190 m 2 g À1 . After Pt deposition, they have measured an ECSA of 23 m 2 g Pt À1 and an ORR onset in the potential range of 0.90-0.95 V RHE .…”