1. |
- Han, Ning, et al.
(författare)
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Achieving Efficient Electrocatalytic Oxygen Evolution in Acidic Media on Yttrium Ruthenate Pyrochlore through Cobalt Incorporation
- 2023
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 33:20
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Tidskriftsartikel (refereegranskat)abstract
- The development of electrocatalysts for the oxygen evolution reaction (OER) especially in acidic media remains the major challenge that still requires significant advances, both in material design and mechanistic exploration. In this study, the incorporation of cobalt in Y2-xCoxRu2O7−δ results in an ultrahigh OER activity because of the charge redistribution at eg orbitals between Ru and Co atoms. The Y1.75Co0.25Ru2O7−δ electrocatalyst exhibits an extremely small overpotential of 275 mV in 0.5 m H2SO4 at the current density of 10 mA cm−2, which is smaller than that of parent Y2Ru2O7−δ (360 mV) and commercial RuO2 (286 mV) catalysts. The systematic investigation of the composition related to OER activity shows that the Co substitution will also bring other effective changes, such as reducing the bandgap, and creating oxygen vacancies, which result in fast OER charge transfer. Meanwhile, the strengthening of the bond hybridization between the d orbitals of metal (Y and Ru) and the 2p orbitals of O will intrinsically enhance the chemical stability. Finally, theoretical calculations indicate that cobalt substitution reduces the theoretical overpotential both through an adsorbate evolution mechanism and a lattice oxygen-mediated mechanism.
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2. |
- Han, Ning, et al.
(författare)
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Lowering the kinetic barrier via enhancing electrophilicity of surface oxygen to boost acidic oxygen evolution reaction
- 2024
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Ingår i: Matter. - 2590-2393 .- 2590-2385. ; 7:3, s. 1330-1343
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Tidskriftsartikel (refereegranskat)abstract
- The acidic oxygen evolution reaction (OER) is essential for many renewable energy conversion and storage technologies. However, the high energy required to break the strong covalent O-H bond of H2O in acidic media results in sluggish OER kinetics. Here, we report the critical role of iron in a new family of iron-containing yttrium ruthenate (Y2-xFexRu2O7-δ) electrocatalysts in highly increasing the electrophilicity of surface oxygen, leading to a significant reduction of the kinetics barrier by 33%, thus an exceptional OER mass activity of 1,021 A· up to 12.4 and 7.7 times that of Y2Ru2O7-δ and RuO2, respectively. Introducing iron reduces the Mulliken atomic charge on the O sites in the generated Ru-O-Fe structure, thereby facilitating the acid-base nucleophilic assault from H2O and reducing the free energy on the rate-determining step of OER. This work provides an effective strategy to reduce the kinetics barrier to achieve highly efficient and economic OER in acidic conditions.
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3. |
- Pang, Kanglei, 1993-, et al.
(författare)
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Redirecting configuration of atomically dispersed selenium catalytic sites for efficient hydrazine oxidation
- 2024
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Ingår i: Matter. - 2590-2393 .- 2590-2385. ; 7:2, s. 655-667
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the reconstruction of surface sites is crucial for gaining insights into the true active sites and catalytic mechanisms. While extensive research has been conducted on reconstruction behaviors of atomically dispersed metallic catalytic sites, limited attention has been paid to non-metallic ones despite their potential catalytic activity comparable or even superior to their noble-metal counterpart. Herein, we report a carbonaceous, atomically dispersed non-metallic selenium catalyst that displayed exceptional catalytic activity in the hydrazine oxidation reaction (HzOR) in alkaline media, outperforming the noble-metal Pt catalysts. In situ X-ray absorption spectroscopy (XAS) and Fourier transform infrared spectroscopy revealed that the pristine SeC4 site pre-adsorbs an ∗OH ligand, followed by HzOR occurring on the other side of the OH–SeC4. Theoretical calculations proposed that the pre-adsorbed ∗OH group pulls electrons from the Se site, resulting in a more positively charged Se and a higher polarity of Se–C bonds, thereby enhancing surface reactivity toward HzO/R.
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4. |
- Zhang, Wei, et al.
(författare)
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Critical Role of Phosphorus in Hollow Structures Cobalt-Based Phosphides as Bifunctional Catalysts for Water Splitting
- 2022
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:4
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Tidskriftsartikel (refereegranskat)abstract
- Cobalt phosphides electrocatalysts have great potential for water splitting, but the unclear active sides hinder the further development of cobalt phosphides. Wherein, three different cobalt phosphides with the same hollow structure morphology (CoP-HS, CoP2-HS, CoP3-HS) based on the same sacrificial template of ZIF-67 are prepared. Surprisingly, these cobalt phosphides exhibit similar OER performances but quite different HER performances. The identical OER performance of these CoPx-HS in alkaline solution is attributed to the similar surface reconstruction to CoOOH. CoP-HS exhibits the best catalytic activity for HER among these CoPx-HS in both acidic and alkaline media, originating from the adjusted electronic density of phosphorus to affect absorption–desorption process on H. Moreover, the calculated ΔGH* based on P-sites of CoP-HS follows a quite similar trend with the normalized overpotential and Tafel slope, indicating the important role of P-sites for the HER process. Moreover, CoP-HS displays good performance (cell voltage of 1.67 V at a current density of 50 mA cm−2) and high stability in 1 M KOH. For the first time, this work detailly presents the critical role of phosphorus in cobalt-based phosphides for water splitting, which provides the guidance for future investigations on transition metal phosphides from material design to mechanism understanding.
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5. |
- Han, Ning, et al.
(författare)
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Rational design of Ruddlesden–Popper perovskite electrocatalyst for oxygen reduction to hydrogen peroxide
- 2022
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Ingår i: SusMat. - : Wiley. - 2766-8479 .- 2692-4552. ; 2:4, s. 456-465
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Tidskriftsartikel (refereegranskat)abstract
- Although the oxygen reduction process to hydrogen peroxide (H2O2) is a green option for H2O2 generation, the low activity and selectivity hindered the industry's process. In recent years, the electrochemical synthesis of H2O2 through a 2e– transfer method of oxygen reduction reaction (ORR) has piqued the interest of both academics and industry. Metal oxide catalysts have emerged as a novel family of electrochemical catalysts due to their unusual physical, chemical, and electrical characteristics. In this work, we first developed a Ruddlesden–Popper perovskite oxide (Pr2NiO4+δ) as a highly selective and active catalyst for 2e– ORR to produce H2O2. Molybdenum was introduced here to adjust the oxidation states of these transition metals with successful substitution into Ni-site to prepare Pr2Ni1-xMoxO4+δ, and the molybdenum substitution improves the H2O2 selectivity during the ORR process, in 0.1 M KOH, from 60% of Pr2NiO4+δ to 79% of Pr2Ni0.8Mo0.2O4+δ at 0.55 V versus RHE. A limiting H2O2 concentration of 0.24 mM for Pr2NiO4+δ and 0.42 mM for Pr2Ni0.8Mo0.2O4+δ was obtained at a constant current of 10 mA/cm2 using a flow-cell reactor using a gas-diffusion electrode.
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7. |
- Zhang, Wei, et al.
(författare)
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Balancing Adsorption, Catalysis, and Desorption in Cathode Catalyst For Li–S Batteries
- 2023
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Ingår i: Advanced Energy Materials. - 1614-6832 .- 1614-6840. ; 13:43
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Tidskriftsartikel (refereegranskat)abstract
- The complicated electrochemical catalytic conversion process of polysulfides in metal–sulfur batteries involves three steps: adsorption, catalysis, and desorption process. Even as huge efforts are made for the understanding of the separate steps (especially for the adsorption and catalysis process), research focusing on the entire process is still scarce. Herein, a series of cobalt phosphides (CoP, CoP2, and CoP3) is employed with identical hollow morphology as model electrocatalysts to investigate the significance of the desorption process and discuss the balancing among the adsorption, catalysis, and desorption of lithium polysulfides (LiPSs). The experimental data demonstrate that, compared to CoP and CoP3, CoP2 exhibits moderate adsorption of LiPSs, which enhances the reduction kinetics of S8 to Li2S and regulates the desorption of short-chain LiPSs. Theoretical calculations further confirm that CoP2 with moderate adsorption of LiPSs exhibits better redox kinetics of LiPSs compared to CoP and CoP3. Moderate adsorption enables the CoP2-based sulfur cathode to deliver excellent stability with 86% capacity retention (2.6 and 2.0 times higher than CoP and CoP3, respectively) over 1000 cycles at 1 C. All these results indicate that in the adsorption-catalysis-desorption chain for LiPSs, all steps need to be considered rather than just focusing on one step of the process.
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9. |
- Borthakur, Dulal, et al.
(författare)
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Current status and trends in forest genomics
- 2022
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Ingår i: Forestry Research. - : Maximum Academic Press. - 2767-3812. ; 2
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Forskningsöversikt (refereegranskat)abstract
- Forests are not only the most predominant of the Earth's terrestrial ecosystems, but are also the core supply for essential products for human use. However, global climate change and ongoing population explosion severely threatens the health of the forest ecosystem and aggravtes the deforestation and forest degradation. Forest genomics has great potential of increasing forest productivity and adaptation to the changing climate. In the last two decades, the field of forest genomics has advanced quickly owing to the advent of multiple high-throughput sequencing technologies, single cell RNA-seq, clustered regularly interspaced short palindromic repeats (CRISPR)-mediated genome editing, and spatial transcriptomes, as well as bioinformatics analysis technologies, which have led to the generation of multidimensional, multilayered, and spatiotemporal gene expression data. These technologies, together with basic technologies routinely used in plant biotechnology, enable us to tackle many important or unique issues in forest biology, and provide a panoramic view and an integrative elucidation of molecular regulatory mechanisms underlying phenotypic changes and variations. In this review, we recapitulated the advancement and current status of 12 research branches of forest genomics, and then provided future research directions and focuses for each area. Evidently, a shift from simple biotechnology-based research to advanced and integrative genomics research, and a setup for investigation and interpretation of many spatiotemporal development and differentiation issues in forest genomics have just begun to emerge.
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10. |
- Chai, Jiali, et al.
(författare)
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Insights on Titanium-based chalcogenides TiX2 (X = O, S, Se) as LIBs/SIBs anode materials
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 453
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Forskningsöversikt (refereegranskat)abstract
- Ti-based chalcogenides TiX2 (X = O, S, Se) are widely used in the research of battery electrode materials due to its excellent rate performance and good chemical stability. In this paper, in order to improve the electrochemical performance of lithium-ion batteries (LIBs) and sodium ion batteries (SIBs), and further improve the application prospect of batteries, the strategies for design and preparation of LIBs/SIBs anode materials for Ti-based chalcogenides TiX2 (X = O, S, Se) are reviewed. The effects of the internal morphology modification, surface structure vacancy and composite with other material of TiX2 (X = O, S, Se) as LIBs/SIBs anode materials are analyzed in detail. On this basis, the application prospect of TiX2 (X = O, S, Se) as LIBs/SIBs anode is prospected, it is expected to fill the research of diversified applications of LIBs/SIBs anode materials.
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