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• The catalysts were synthesized by dealloying melt-spun ribbons. • The optimal processed ribbons exhibited excellent catalytic performance. • Dealloying treatment achieved faster kinetics and more active sites. • Dealloying decreased the water dissociation and hydrogen absorption energy. The development of high-performance and low-cost alkaline hydrogen precipitation catalysts is critical for the large-scale application of hydrogen energy. In this work, the nanoporous alloy catalysts were synthesized by dealloying melt-spun NiZrPt ribbons. The optimal sample after dealloying shows excellent HER performance in alkaline medium, with a small overpotential of 15 mV to deliver 10 mA cm−2 and a low Tafel slope of 20 mV/dec. The material characterization reveals that the incorporation of Ni modulates the electronic structure of Pt. After selective dealloying of Zr and Ni, a Pt-enriched nanoporous structure was formed on the catalyst surface. Meanwhile, the remaining Ni sites acted as synergistic sites to activate the Pt sites, which allowed for better hydrogen adsorption energy and faster kinetics of the catalytic reaction. Besides, the favorable mechanical flexibility of the material makes it potential for self-supporting electrode. This work presents a way to prepare low-Pt efficient catalysts by amorphous alloy dealloying. [ABSTRACT FROM AUTHOR]

A bottom-up method for the preparation of platinum nanoparticles (PtNPs)-decorated two-dimensional (2D) metal–organic framework (MOF) nanocomposites was developed with a maximum water decomposition rate of 3348 μmol g-1h−1 and sufficient stability. [Display omitted] • The Zr-TCPP(Pd) and Zr-TCPP ultrathin nanosheets were successfully synthesized. • The nanosheets modified with Pt NPs show excellent photocatalytic performance. • DFT revealed the importance of Pd-doping position in Pt 79 NPs on the activity. Edge-doping engineering in metal nanoparticles (MNPs) is always hard to achieve due to the high surface energy of the hybrid MNPs, while porphyrin-based ultrathin two-dimensional (2D) metal–organic framework (MOF) is demonstrated the positive role in stabilize this structure. Herein, a bottom-up method was developed to prepare platinum nanoparticles (PtNPs)-decorated 2D MOF nanosheets, where a porphyrin ligand of Pd-metalized tetrakis(4-carboxyphenyl)porphyrin (PdTCPP) was applied to synthesize ultrathin MOF nanosheets as Zr-TCPP(Pd) in high yield. Attributing to the high superficial area of ultrathin Zr-TCPP(Pd) nanosheets, Pt NPs can well anchor uniformly with small nanoparticle size to obtain 2% Pt/Zr-TCPP(Pd) hybrid nanosheets, which showed a higher photocatalytic hydrogen production rate of 3348 μmol g-1h−1. This is attributed to the coordination between Zr4+ and C = O of PVP, which promotes the contact between PtNPs and Zr-TCPP(Pd) nanosheets. As a result, the long-life electrons of PdTCPP photosensitizers are rapidly transferred to the electron capture center PtNPs, and the photoelectron-hole recombination is effectively inhibited. The apparent quantum efficiency of 2% Pt/Zr-TCPP(Pd) reaches up to 1.56% at 420 nm. The density functional theory (DFT) calculations revealed the Pd-doped position in Pt 79 nanoparticle is important that the Pt 78 Pd surf. model (Pd atom was doped on the surface of Pt nanoparticle) showed the highest activity with abundant exposed active region. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe x Mn y mixed oxide catalysts with various Mn/Fe + Mn were prepared by co-precipitation. • Mn species enters into Fe 2 O 3 or Fe species, into MnOx, to form Fe-O-Mn structure. • Fe-O-Mn promotes the redox and acidity of Fe 2 O 3 , and activation of Fe-OH with O 2. • Fe 2 O 3 with Fe-O-Mn is active and stable in the oxidation of chlorinated aromatics. • No chlorination product is detected over Fe x Mn y catalysts within 1 ppm limitation. Fe x Mn y mixed oxide catalysts prepared by co-precipitation method are applied in catalytic combustion of chlorobenzene (CB) and 1,2-dichlorobenzene (1,2-DCB). Characterization shows that Mn species of Fe 9 Mn 1 highly disperse into α-Fe 2 O 3 as Fe-O-Mn structure. With the increase in Mn content, a part of Mn is separated as MnO 2 and α-Mn 2 O 3. Fe-O-Mn structure greatly increases the acidity (especially for strong acid) and reducibility of α-Fe 2 O 3. In CB and 1,2-DCB oxidations, Fe x Mn y catalysts are active, of which Fe 9 Mn 1 catalyst presents the highest activity. At 5% – 20% O 2 and 500 – 2000 ppm 1,2-DCB at space velocity of 15,000 mL g-1h−1, the apparent rates at 300 °C over Fe 9 Mn 1 are estimated to be 0.056 – 0.112 μmol min−1 m−2, and the temperatures needed for 50% and 90% conversions are 294 – 342 °C and 346 – 375 °C, respectively. High availabilities of surface oxygen and acid sites are related to effective Cl removal in aid of active hydroxyls produced during the reaction (confirmed by in situ FT-IR tests), which are responsible for high activity of Fe 9 Mn 1 catalyst. For the catalysts with MnO 2 and Mn 2 O 3 domains on the surface, Cl strong adsorption results in their deactivation. Moreover, Fe 9 Mn 1 catalyst shows high stability at 350 °C on feed stream containing 1000 ppm 1,2-DCB within 600 min duration or for five runs. The selectivity for CO/CO 2 approaches 98% or higher and no chlorination products are detected within FID limitation (1 ppm) under the above mentioned broad reaction conditions, which are highly desirable for industrial application. [ABSTRACT FROM AUTHOR]

This work reports a carbon nanotube cross-linking MOF-derived Fe/N/C catalysts for oxygen reduction electrocatalysts in fuel cell and lithium-oxygen battery. [Display omitted] • A carbon nanotube cross-linking strategy was designed to enhance Fe/N/C catalyst. • Low-spin and high-spin FeN 4 structures are considered to be a major active site. • For fuel cell, a stable stage is reached after 20 h of reduction. In this work, we report our recent efforts in developing carbon nanotube cross-linking MOF-derived Fe/N/C catalysts as oxygen reduction electrocatalysts for fuel cell. It is witnessed that the carbon nanotube cross-linking strategy can effectively improve the activity and stability of fuel cell, which can be assigned to its fast and convenient electron conduction channels offered by loosely cross-linked carbon nanotubes. The results of 57Fe Mössbauer spectroscopy show that there are three spin states of Fe-N 4 structure in the material, of which low-spin state D1-FeIIN 4 and high-spin state D3-N-FeN 4 are both considered to be the main active sites of oxygen reduction reaction. For fuel cell, high performance of 0.732 A cm−2 at 0.7 V is reached. The novel cross-linking catalyst sheds light on the development of non-precious metal catalysts for fuel cells. [ABSTRACT FROM AUTHOR]

• Enhanced mechanisms of a novel electrocatalytic-ozonation process was investigated. • The novel process shows excellent synergistic effect in ibuprofen destruction. • TiO 2 catalytic layer and electrochemical action significant promoted OH formation. • Anodic TiO 2 catalyst can promote cathodic H 2 O 2 production and O 3 /H 2 O 2 reaction. • Adsorption and transformation of O 3 on anodic TiO 2 interface was highly improved. This study aims to systematically investigate the enhanced mechanism of our previously proposed novel electro-heterogeneous catalytic ozonation (E-catazone) process. In this process, a unique TiO 2 nanoflower (TiO 2-NF)-coated porous titanium gas diffuser served as the anode and aerator at same time, and commercial graphite-coated Ti mesh (Graphite @Ti mesh) acted as cathode. For ibuprofen (k ibuprofen,O3 of 9.6 M−1 s−1), an ozone-resistant pharmaceutical micro-pollutant, as the model-pollutant, E-catazone with the TiO 2-NF anode showed excellent performance and significant synergistic effect for ibuprofen destruction efficiency and rate, and also delivered much higher enhancement ratios of 7.9 and 6.8 for ibuprofen degradation and TOC removal, respectively. The study revealed that OH is the main reactive oxygen species in the degradation of ibuprofen, and that the OH production was largely increased in E-catazone, by approximately two orders of magnitude of that in the ozonation and EO (electrochemical oxidation) processes. Further, TiO 2-NF and electrochemical action were found to play crucial roles in promoting O 3 conversion for enabling the enhanced formation of OH. Surprisingly, we found that the presence of the anode catalyst, TiO 2-NF , can improve the electro-generation of H 2 O 2 by decreasing cathodic potential, while the electrochemical action can also significantly enhance anodic TiO 2-NF interface adsorption and conversion of O 3. The results of computational studies showed that TiO 2 -(OH) 2 is the main site for O 3 adsorption at anodes, and the application of positive overpotential or coating of TiO 2-NF at the anode can significantly improve the interfacial adsorption of O 3. Therefore, E-catazone has great potential for synchronously and effectively promoting heterogeneous and homogeneous catalytic reactions of ozone under the synergistic action of TiO 2-NF and electrochemical action, and shows broad prospects in application for the efficient degradation of pharmaceutical micro-pollutants. [ABSTRACT FROM AUTHOR]