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Developing highly efficient and cost‐effective electrocatalysts for oxygen reduction reaction (ORR) in aqueous media is crucial for energy conversion systems such as fuel cells or Zn‐air batteries. Electrode materials from spent devices such as lithium‐ion batteries (LiBs) are a serious environmental problem. One of the solutions is their reuse for other electrochemical processes. This work demonstrates the application of solid residues of carbon‐based powders left over from the hydrometallurgical recycling process of LIBs' waste as efficient catalysts for ORR. Microscopic and spectroscopic studies of the residue disclosed their porous structure and various cobalt contents, depending on the recycling procedure. These battery wastes display ORR catalytic activity when deposited at the liquid‐liquid and solid electrode‐electrolyte interfaces. Scanning Electrochemical Microscopy (SECM) tests showed that assembling battery waste at the liquid‐liquid interface boosts the efficiency of H2O2 production by one to two orders of magnitude. The catalytic activity towards 2‐electron ORR strongly depends on waste powder compositions and structures, e.g., porosity, heteroatom presence, level of defects, and graphitization. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) derived nanostructures receive immense research focus due to its high porosity, conductivity, and structural tailrolability features. In this work, porous Zeolitic Imidazole Framework‐67 (ZIF‐67) to synthesize cobalt phosphide/carbon composite (ZCoPC) that serves as a positive electrode is utilized. Furthermore, porous and conductive office paper derived carbon (OPC) are utilized as a negative electrode to make a hybrid system. The metalloid characteristics, high conductivity, and good porosity of ZCoPC material makes it a high‐performance battery like electrode. ZCoPC electrode achieves maximum specific capacity of 192.6 mAh g−1 at 1 A g−1 using 1 m potassium hydroxide (KOH) electrolyte. Furthermore, surface and diffusion charge participation investigation are also undergone for ZCoPC electrode that helps in determining the actual charge dynamics occurring in the electrode. In addition, a supercapattery device is assembled using ZCoPC as battery electrode and OPC as supercapacitor electrode. The as fabricated OPC//ZCoPC hybrid supercapattery device delivers extraordinary energy density of 31.6 Wh kg−1 with a power density of 700 W kg−1 and also a long cycle life of 92.3% even after 10,000 charge–discharge cycles. Hence, these outcomes demonstrate that the synergy of porous MOF derived metal phosphide and OPC electrodes are beneficial for supercapattery devices. [ABSTRACT FROM AUTHOR]

The fumed SiO2 and Al2O3 oxides with a specific surface area of about 80 m2 g–1 were used for the synthesis of Ni(80)Fe(20)/SiO2, Co(93)Fe(7)/SiO2, Ni(80)Fe(20)/Al2O3 and Co(93)Fe(7)/Al2O3 nanocomposites, and numbers between brackets indicate the metal content in wt%, being 10 wt% of the mass of catalysts. Catalytically active bimetallic compositions (NiFe and CoFe) that modified the fumed oxides' surface were prepared using the solvate-stimulated method with subsequent thermal decomposition and reduction of the metal oxides to corresponding metals with hydrogen. The catalysts were characterized using the TGA in dynamic hydrogen, nitrogen physisorption, and PXRD methods. The complete conversion of carbon dioxide is observed in the temperature range of 350–425 °C at the maximum methane yield of 72–84%. The long-time catalytic test demonstrates the high stability of the catalyst during 5 weeks of exposure to the reaction mixture. The yield of methane was decreased by 3–14% after 1–2 months of long-time testing. [ABSTRACT FROM AUTHOR]

Compared with the monometallic palladium, bimetallic Pd-Au/SiO2 catalysts show much higher activity and better stability in the reaction of hydrodechlorination of tetrachloromethane, also providing higher selectivity to longer than methane hydrocarbon products. Reasonably mixed Pd-Au particles show better catalytic performance during ~60 h operation, whereas the monometallic palladium and very rich in palladium catalysts suffer rapid deactivation. Smaller amounts of carbon- and chlorine-containing deposits found after reaction on Pd-Au catalysts correspond to their superior catalytic behavior.

The front cover of the journal ChemElectroChem showcases the recycling of spent Li-ion batteries through acid leaching and the use of the resulting solid carbon-based materials as electrocatalysts for generating hydrogen peroxide through oxygen reduction. The article explores the relationship between the structure and composition of the battery waste and its electrocatalytic activity. The research was conducted by a team of authors led by Magdalena Warczak and the cover design was done by Dr. Magdalena Osial. For more information, readers can refer to the Research Article with the DOI: 10.1002/celc.202400248. [Extracted from the article]

Pd/MgO, Pd/MgF2 and Pd/MgO-MgF2 catalysts were investigated in the reaction of CCl4 hydrodechlorination. All the catalysts deactivated in time on stream, but the degree of deactivation varied from catalyst to catalyst. The MgF2-supported palladium with relatively large metal particles appeared the best catalyst, characterized by good activity and selectivity to C2-C5 hydrocarbons. Investigation of post-reaction catalyst samples allowed to find several details associated with the working state of hydrodechlorination catalysts. The role of support acidity was quite complex. On the one hand, a definite, although not very high Lewis acidity of MgF2 is beneficial for shaping high activity of palladium catalysts. The MgO-MgF2 support characterized by stronger Lewis acidity than MgF2 contributes to very good catalytic activity for a relatively long reaction period (~5 h) but subsequent neutralization of stronger acid centers (by coking) eliminates them from the catalyst. On the other hand, the role of acidity evolution, which takes place when basic supports (like MgO) are chlorided during HdCl reactions, is difficult to assess because different events associated with distribution of chlorided support species, leading to partial or even full blocking of the surface of palladium, which plays the role of active component in HdCl reactions. [ABSTRACT FROM AUTHOR]

Abstract: Pd/Nb2O5–Al2O3 catalysts exhibited interesting properties in the hydrodechlorination of dichlorodifluoromethane. Introduction of niobia to alumina increases the selectivity for CH2F2, from ∼40% (for Pd/ Al2O3) up to ∼75%, for similar metal dispersions. High-temperature reduction (773K, HTR) of Pd/Nb2O5–Al2O3 generates the SMSI state, understood as blocking the Pd surface by (partly) reduced niobia. The extent of SMSI effect is judged from a direct comparison between the performance of differently pretreated Pd/Nb2O5–Al2O3 catalysts tested in n-hexane conversion (hydrogenolysis/isomerisation). After HTR of the niobia-containing Pd catalysts, the hydrodechlorination activity disappeared, however the SMSI state became reversed during hydrodechlorination. It is speculated that CCl2F2 and liberated HCl, interact with NbO x decorants, converting them into volatile niobium oxychloride species. [Copyright &y& Elsevier]

A series of Pt/Al2O3 catalysts were prepared by the impregnation method and were characterized by TEM, XRD, H2 and CO chemisorptions, and investigated in the hydrodechlorination of tetrachloromethane. Three Pt-rich, Pt–Au/Al2O3 catalysts (Pt100, Pt95Au5 and Pt90Au10) showed a similar metal particle size (~2.5–2.7 nm), so observed changes in the catalytic behavior are ascribed to alloying effect, especially because a considerable degree of Pt–Au mixing was achieved in the bimetallic samples. It appeared that by introducing very small amount of gold (10 at.%) to platinum, the catalytic activity is increased. It is argued that the occurrence of this moderate synergistic effect is associated with a decreased tendency of surface chloriding when platinum is alloyed with gold. [ABSTRACT FROM AUTHOR]