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Summary: Graphitic carbon nitride is of interest for its intercalation, ion exchange, and redox properties as it exhibits high catalytic activity. Besides, its high nitrogen content and facile synthesis procedure may provide a good balance between activity and durability. We report novel g‐C3N4 based MOF as a novel electrocatalyst for methanol oxidation reaction (MOR). Two methods are involved in the catalytic synthesis, namely the hydrothermal method for the Cu/Ni MOF and its composites synthesis, and g‐C3N4 is obtained by pyrolysis of melamine. To explore the structural and morphological properties, all the catalysts were eventually characterized using XRD, FTIR, SEM, and EDX techniques, whereas cyclic voltammetry (CV) revealed the electrochemical response for the oxidation of methanol in 3 M methanol and 1 M NaOH on modified glassy carbon electrode (GCE). The electrochemical results illustrate that as the amount of g‐C3N4 increases current density for methanol oxidation reaction (MOR). The maximum current density is 103.42 mA/cm2 shown by Cu/Ni MOF@5 wt% g‐C3N4 at 0.9 V while the scan rate is 50 mV/s. Thus, graphitic carbon nitride addition in MOF composites enhanced its durability and high carbon monoxide (CO) tolerance makes active catalysts in alkaline electrolyte. [ABSTRACT FROM AUTHOR]

In this study, biomass derived activated carbon (AC) was utilized to enhance the electrochemical properties of copper benzene-1, 3, 5-tricarboxylate metal organic framework (Cu-BTC MOF). Dried leaves (Lantana) were activated with phosphoric acid (H3PO4) for preparation of AC. Cu-MOF was pyrolyzed with different ratios of AC (1:1) under a reduction atmosphere of mixture of argon and hydrogen gases (90:10) in a tube furnace. These freshly produced composite materials were examined by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and thermal gravimetric analysis. The synthesized catalysts were tested for its electro catalytic activity for oxidation reduction reaction (ORR) in three electrode system by cyclic voltammetry, Tafel polarization and electrochemical impedance spectroscopy. The electrochemical parameters calculated by film coated glassy carbon electrode exhibit impact of activated carbon on oxidation reduction reaction catalyzed by Cu-BTC MOF. The composite Cu@AC (1:1) reported the highest current density of 2.11 mA cm−2 at 0.9 V potential with a scan rate of 50 mV s−1 in 0.1 M KOH which is better than commercial grade Pt/C having highest current density of 1.37 mA cm−2 at 0.86 V potential. The electrochemical activity and intensified constancy is due to synergistic influence of MOF and AC-composite. [ABSTRACT FROM AUTHOR]

This work utilized an innovative and economical remediation method to convert inexpensive waste feedstock into extremely useful catalysts. The procedure centered on polyethylene (PE), an easily accessible substance, and effectively transformed it at a mild temperature utilizing a new solvothermal technique, which entailed the reaction of sulfuric acid with PE chains at 120 °C. Throughout this process, the polymer experienced a pivotal cross-linking stage, resulting in its conversion into carbon materials when exposed to temperatures above 500 °C. To improve the catalytic characteristics, platinum (Pt) was effectively integrated into the resultant carbon matrix using the existing impregnation technique. Further, the catalyst's physicochemical properties were thoroughly analyzed utilizing SEM, FTIR, and XRD techniques. After that, the catalyst's performance was thoroughly evaluated in several electrocatalytic reactions, such as methanol oxidation, oxygen evolution and reduction reactions, and hydrogen evolution. The results of this investigation reveal the impressive electrocatalytic ability of the Pt/C catalyst made from waste plastic. It was found to be comparable to the best commercially available Pt/C catalysts in all the reactions that were examined. This research not only demonstrates the possibility of using waste plastic for catalyst production, but also serves as the first documented example, based on successfully converting waste plastic bags into Pt/C through the conventional Liquid Phase Reduction (LPR) process. This novel method has great potential for sustainable and ecologically responsible catalytic applications. • The waste plastic derived Pt/C catalyst was prepared by solvothermal method. • For MOR plastic derived Pt/C shows electrocatalytic activity of 96.74 mA/cm2 current density and 46 % stability. • For OER it attain a current density of 10 mA/cm2 at a potential of 1.65 V. • For HER achieve current density of 10 mA/cm2 at a low voltage of 39.1 mV. • For ORR it exhibits −2.80 mA cm⁻2 of current density and half potential of 0.86 V. [ABSTRACT FROM AUTHOR]

For metal air batteries the synthesis of highly efficient, sustainable, non-precious metal-based electrocatalysts with bifunctional catalytic activity for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are essential. In this work via simple hydrothermal method Cu MOF and its g-C 3 N 4 based composites are prepared and characterized via FTIR, XRD, SEM and EDX. The Cu MOF and the g-C 3 N 4 -based electrode can work synergistically to enhance the electrochemical process. The Cu MOF accepts electrons, and the g-C 3 N 4 -based electrode donates them. Consequently, improving electron transport between the electrode and oxygen molecule accelerates reaction kinetics. Further, via incorporating g-C 3 N 4 in Cu MOF makes the charge transfer between the electrode and electrolyte effective, making it a viable option for electrochemical devices. In stable states, Cu MOF with 5 wt% of graphitic carbon nitride has a low overpotential (389 mV/10 mA/cm2), a Tafel slope of 26.12 mV/dec, and high stability over 3600 s in 1 M KOH. EIS result showed that g-C 3 N 4 decreases charge transfer resistance by allowing electroactive species to contact the catalyst. Further, via three-electrode setup under nitrogen and oxygen conditions at different scan speeds ORR analysis is done. The composite Cu MOF (5 wt%) exhibits the maximum current density of 1.31 mA/cm2 at 0.05 mV /s scan rate in 1 M KOH, surpassing the original Cu MOF, which produced 1.09 mA/cm2. • Cu MOF and its g-C 3 N 4 based composites, synthesized via Hydrothermal method, and characterized via FTIR, XRD, SEM and EDX. • Electrochemical activity is tested in 1 M KOH via CV, EIS, CA and LSV. • For OER Cu MOF/ 5 wt% @ g-C 3 N 4 show low overpotential of 389 mV at 10 mA/cm2, 26.12 mV /dec (Tafel slope). • For ORR Cu MOF/ 5 wt% @ g-C 3 N 4 show an onset potential of 0.88 V vs RHE, and exhibit good stability after 1000 ORR cycles. [ABSTRACT FROM AUTHOR]

In this study, zeolitic imidazolate framework (ZIF-67) derived nano-porous carbon structures that were further hybridized with MnO2 were tested for oxygen reduction reaction (ORR) as cathode material for fuel cells. The prepared electrocatalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Energy Dispersive X-ray Analysis (EDX). Cyclic voltammetry was performed on these materials at different scan rates under dissolved oxygen in basic media (0.1 M KOH), inert and oxygen rich conditions to obtain their I–V curves. Electrochemical impedance spectroscopy (EIS) and Chronoamperometry was also performed to observe the materials' impedance and stability. We report improved performance of hybridized catalyst for ORR based on cyclic voltammetry and EIS results, which show that it can be a potential candidate for fuel cell applications. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) have been at the center stage of material science in the recent past because of their structural properties and wide applications in catalysis. MOFs have also been used as hard templates for the preparation of catalysts. In this study, highly active CuPt/NC electrocatalyst was synthesized by pyrolyzing Cu-tpa MOF along with Pt precursor under flowing Ar-H2 atmosphere. The catalyst was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). Rotating disk electrode study was performed to determine the oxygen reduction reaction (ORR) activity for CuPt/NC in 0.1 M HClO4 at different revolutions per minute (400, 800, 1200, and 1600) and it was also compared with commercial Pt/C catalyst. Further the ORR performance was evaluated by K-L plots and Tafel slope. CuPt/NC shows excellent ORR performance with onset potential of 0.9 V (vs. RHE), which is comparable with commercial Pt/C. The ORR activity of CuPt/NC is demonstrated as an efficient electrocatalyst for fuel cell. [ABSTRACT FROM AUTHOR]

• Mo-MOF, MO/NPC and MO-MS/NPC were synthesized via solvothermal method at 200 °C and pyrolysis. • All prepared composites were characterized via SEM, TEM, FTIR, XRD and XPS. • Synthesized series is tested for methanol oxidation and for oxygen reduction reactions. • MO-MS/NPC demonstrate higher electrochemical activity such as exhibiting 354.2 mA/cm2 current density for MOR and −9.54 ma/cm2 for ORR with low overpotential value of 0.80 V. In this paper, an effective method for synthesizing three different catalysts Mo-MOF, MO/NPC, and MO-MS/NPC by solvothermal preparation and pyrolysis processes has been described. The structural and compositional characteristics of these catalysts have been thoroughly analyzed using SEM, XRD, XPS, FTIR, and TEM characterization techniques. It is noteworthy that MO-MS/NPC has proven to have remarkable electrocatalytic capabilities, exhibiting high current density i.e., 354.3 mA/cm2 and stability in methanol oxidation as well as superior electrocatalytic activity for oxygen reduction reactions Because of these qualities, MO-MS/NPC, MO/NPC, and Mo-MOF might be an attractive option as cathodic and anodic materials in direct methanol fuel cells (DMFCs). Their higher oxygen reduction abilities as cathode materials can boost the cathodic reaction's effectiveness and encourage the conversion of oxygen and protons into water, and also help methanol to oxidize into carbon dioxide at the anode, liberating electrons that can be used to produce electricity. [ABSTRACT FROM AUTHOR]

• Nanostructured composites Mn/Zn N C @30% rGO, Mn/Zn N C @20% rGO, Mn/Zn N C @10% rGO was synthesized. • Mn/Zn N C @30% rGO demonstrates good electrocatalytic ORR activity in alkaline aqueous electrolyte solutions. • Mn/Zn N C @30% rGO has the lowest Tafel slope overpotential for attaining superior current density. • Mn/Zn N C @30% rGO has been proven reliable for test as fuel cross-over in methanol. Future fuel cells and metal-air batteries will benefit greatly from revealing self-supported electrodes with efficient oxygen reduction reaction (ORR) activity and durability. However, noble metal catalysts are expensive and unstable, necessitating research into novel metal-organic framework (MOF)-based topologies that can catalyse oxygen reduction reactions (ORR). In this work, the synthesis of nitrogen-doped carbon (N C) is derived from zeolitic imidazolate frameworks (ZIFs) and a novel Mn-doped Zn N C@rGO is synthesized using a self-templated solvothermal method and their performance in an alkaline medium for oxygen reduction reaction (ORR) is studied. The nanostructured composite outperformed the commercial Pt/C catalyst in terms of both material resources and application efficacy. The Mn/Zn N C @30% rGO exhibit outstanding performance for ORR in KOH, with a more positive cathodic peak of 0.78 V vs RHE and an onset potential of 0.97 V vs RHE, which are characteristics that suggest the possibility of reducing ORR overpotentials. The improved electrochemical performance, small Tafel slopes and methanol tolerance are ascribed to the interdependent effect of the N -doped carbon (N C) and the Mn/Zn active sites. Novel architecture, tunable porosities, template directed growth and remarkable electrocatalytic performance of Mn-doped Zn N C@rGO make it a good aspirant for energy applications. [ABSTRACT FROM AUTHOR]

For alkaline fuel cell, development of highly efficient catalysts based on non-noble metal for oxygen reduction reaction is of high significance. In this work, synthesis of nitrogen doped carbon nanotubes (NCNTs) derived from Zeolitic Imidazolate Frameworks (ZIFs) and their performance for oxygen reduction reaction (ORR) in alkaline medium are studied. The NiCo/NCNTs (nitrogen doped carbon nanotubes) showing excellent ORR performance in KOH with current density of −5.6 mA cm−2 and onset potential of 0.98 V vs RHE. The improved electrochemical performance and stability is credited to the synergetic effect of the nitrogen doped carbon nanotubes (NCNTs) and the Ni/Co active sites. The alkaline fuel cell performance of NiCo/NCNTs as cathode catalyst was 65 mW cm−2, which is slightly higher than the commercial Pt/C as cathode (60 mW cm−2). These results indicate that NiCo/NCNTs are promising electrocatalysts for ORR in alkaline fuel cell. Image 1026449 • The NiCo/NCNTs showed halfwave potential of 0.88V while Pt/C showed 0.84V. • In AFC, NiCo/NCNTs showed peak power density of 65 mW cm−2. • Synergetic effect of the NCNTs and the Ni/Co active sites. [ABSTRACT FROM AUTHOR]

• Pt/Pt alloy and single Pt atoms are anchored on defects rich carbon support. • PtNiCo/NC showed halfwave potential of 0.91 V while Pt/C showed 0.87 V. • PtNiCo/NC catalyst showed a peak power density of 1070 mWcm−2. • PtNiCo/NC exhibited excellent stability in fuel cell with no loss in performance. • Synergistic effect among nitrogen doped carbon, Co/Ni active sites and Pt/Pt alloy. High performance cathode catalysts with minimum platinum amount for the electrocatalyzed oxygen reduction reaction (ORR) in PEMFCs remain as a significant challenge for commercial application. Zeolitic Imidazolate Framework (ZIF) based catalyst can provide void 3D framework of N-doped nano-porous carbon for promising ORR activity. Here we report a bimetallic pyrolyzed NiCo-ZIF supported fine Pt/Pt alloy electrocatalyst for ORR. After pyrolysis, nano-porous carbon is obtained with well dispersed Pt/Pt alloy nanoparticles (˜ 3 nm). This catalyst shows superior performance and stability in acidic medium against the commercial catalyst comprising of Pt/C. In a single cell PEMFC, high peak power density value of 1067 mW. cm−2 is attained at 70 °C by using low platinum amount of 0.12 mg cm-2 on cathode. The enhanced activity and durability is credited to the synergistic impact of N-doped nano-porous carbon originated from NiCo-ZIF and the defect rich carbon support to anchor Pt/Pt alloy nanoparticles. [ABSTRACT FROM AUTHOR]