Litchi‐derived platinum group metal‐free electrocatalysts for oxygen reduction reaction and hydrogen evolution reaction in alkaline media

Abstract

Within the framework of the circular economy, the waste litchi's skins were upgraded and transformed into electrocatalysts for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). The waste litchi's skins were pyrolyzed, activated, and then used as carbon support for fabricating metal–nitrogen–carbons (M–N–Cs) which belong to a promising class of platinum group metal‐free electrocatalysts. The activated char was functionalized with transition metal (Fe, Ni, and Co)‐ phthalocyanine (Pc) in monometallic and bimetallic fashion by subjecting it to a thermal treatment at 600 and 900°C. The samples functionalized at 900°C showed higher performance for HER due to the formation of metal nanoparticles, whereas the samples functionalized at 600°C showed higher performance for ORR. Particularly, sample Ni–Co 900 had an overpotential of −0.38 V for HER, while the sample Fe 600 was the most active electrocatalyst for ORR by demonstrating the onset potential of ∼0.9 V (a half‐wave potential of ∼0.81 V) with the least production of unwanted peroxide anion.

Mono-, bi- and tri-metallic Fe-based platinum group metal-free electrocatalysts derived from phthalocyanine for oxygen reduction reaction in alkaline media

“…The X-ray source was the monochromatic Alk α at a power of 350 W, as previously reported. 97–99 XPS data were processed with MultiPak V6.1A software linked to the MatLab server, and the data were discussed while keeping into account similar M–N–C electrocatalysts reported in the literature. 79–84…”

Electrochemical investigations and antimicrobial activity of Au nanoparticles photodeposited on titania nanoparticles

“…Because of the relatively slow kinetics of oxygen generation and breakdown on most electrodes, the oxygen reduction reaction (ORR) considerably restricts the wide-ranging use of fuel cells [ 24 ]. In these applications, platinum (Pt)and its alloys are primarily employed as anodic and cathodic catalysts, but this metal is expensive and has a finite supply [ 25 , 26 ].…”

Transforming Cigarette Wastes into Oxygen Reduction Reaction Electrocatalyst: Does Each Component Behave Differently? An Experimental Evaluation

“…Therefore, a huge academic interest has recently been witnessed in the utilization of plastics and biomass waste. [13,[36][37][38] Recently, different waste materials such as polyethylene terephthalate (PET) packaging [39] and bottles, [40] facemasks, [36] polypropylene lunchboxes, [23] waste tires, [37] polyurethane, [13] pistachio shells, [41] waste tea, [42] waste leather, [43] spent batteries, [44] several bio-based waste [45][46][47] and so on have been utilized as a carbon feedstock to develop PGM-free catalysts i. e. FeÀ NÀ Cs for ORR via pyrolysis. With the same pursuit, recently, our research group attempted to synthesize Fe-N x -Cs catalysts for ORR starting from cigarette butts [48] optimizing the synthesis process in two-step pyrolysis at 450 °C and 600 °C, with an intermediate activation process to increase the surface area.…”