Molybdenum Carbide/Ni Nanoparticles Embedded into Carbon Nanofibers as an Effective Non-Precious Catalyst for Green Hydrogen Production from Methanol Electrooxidation

Abstract

Molybdenum carbide co-catalyst and carbon nanofiber matrix are suggested to improve the nickel activity toward methanol electrooxidation process. The proposed electrocatalyst has been synthesized by calcination electrospun nanofiber mats composed of molybdenum chloride, nickel acetate, and poly (vinyl alcohol) under vacuum at elevated temperatures. The fabricated catalyst has been characterized using XRD, SEM, and TEM analysis. The electrochemical measurements demonstrated that the fabricated composite acquired specific activity for methanol electrooxidation when molybdenum content and calcination temperature were tuned. In terms of the current density, the highest performance is attributed to the nanofibers obtained from electrospun solution having 5% molybdenum precursor compared to nickel acetate as a current density of 107 mA/cm2 was generated. The process operating parameters have been optimized and expressed mathematically using the Taguchi robust design method. Experimental design has been employed in investigating the key operating parameters of methanol electrooxidation reaction to obtain the highest oxidation current density peak. The main effective operating parameters of the methanol oxidation reaction are Mo content in the electrocatalyst, methanol concentration, and reaction temperature. Employing Taguchi’s robust design helped to capture the optimum conditions yielding the maximum current density. The calculations revealed that the optimum parameters are as follows: Mo content, 5 wt.%; methanol concentration, 2.65 M; and reaction temperature, 50 °C. A mathematical model has been statistically derived to describe the experimental data adequately with an R2 value of 0. 979. The optimization process indicated that the maximum current density can be identified statistically at 5% Mo, 2.0 M methanol concentration, and 45 °C operating temperature.

A Recent Review of Electrospun Porous Carbon Nanofiber Mats for Energy Storage and Generation Applications

“…Functionalized nanofibers can promote the activation of persulfate or other oxidants, leading to the efficient degradation of pollutants in water or air [119]. As catalysts in energy conversion and storage devices, such as supercapacitors or lithium-ion batteries, porous carbon nanofibers can improve electrochemical performance by improving charge transfer kinetics and increasing electroactive surface area [120]. Also, as catalysts in various chemical synthesis reactions, including organic transformations, hydrogenations, oxidations, and coupling reactions, the large surface area and catalytic activity of nanofibers facilitate efficient reaction pathways and promote the formation of the desired product in chemical industries [121].…”

One pot synthesis of hydrogen and glucaric acid via glucose electrolysis

“…For glucose oxidation, electron transfer is known to be mediated by Ni(OH) 2 /NiO(OH) redox couple, and participates in the rate limiting step of the electro-oxidation. 39,40 Additionally, Ni incorporating another metal/carbon matrix with heteroatom enhances the electron transfer, conductivity and is important for direct efficient electro-oxidation of glucose 41,42 and hydrogen production. 43 The activity of bimetallic electrocatalysts depends on the combined electronic effect of both metals.…”