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Funding: This research is supported by the EPSRC-DST India-UK project EPI037016/1. This work is also partially supported by the Sichuan Science and Technology Program (under agreement nos. 2021YFH0222 and 2019YFH0177). The authors acknowledge the Zigong Science and Technology Program (under agreement nos. 2020YGJC18 and 2019YYJC24). Ni-YSZ (nickel-yttrium-stabilized zirconia) is a common anode for solid oxide fuel cells (SOFCs) because of its excellent catalytic performance and electronic conductivity. It shows that the nickel anode-supported cell exhibits good cell performance in a biogas fuel of 36CH4-36CO2-20H2O-4H2-4CO. Unfortunately, natural biogas fuels often contain sulfur, so using nickel anodes is not always straightforward. This paper investigates the sulfur poisoning and the recovery of BaCe0.7Zr0.1Y0.1Yb0.1O3-δ- (BCZYYb-) (Ce, Y, and Yb codoped barium zirconate) impregnated nickel anode-supported cells operating up to 1.8 W cm-2 in the biogas. The in situ gas analysis reveals that the suppression of the reforming reactions might cause sulfur poisoning in a 4 ppm (v) H2S (hydrogen sulfide) in open circuit conditions, whereas the current degradation in working conditions could be attributed to the deactivation of reforming reactions and catalyst activity. The incidence of water-gas shift reactions is associated with the degradation rate of these two reactions. After removing the H2S, the recovery is accelerated by a steam hydrogen fuel, indicating that steam facilitates the efficient release of sulfur from nickel sites. Publisher PDF

Here we report the synthesis and properties of some lead-free organic bismuth halides. β-(PPD)2Bi2I10 has the longest average charge carrier lifetime (>1 μs) of the materials studied here, of the same order of magnitude as that of (CH3NH3)PbI3 and has a low band gap.

Funding: This research was supported by EPSRC research grants EP/R023522/1, EP/T019298/1, EP/R023751/1, EP/L017008/1 the China Scholarship Commission (MW) received financial support from the UK Catalysis Hub funded by EPSRC Grant reference EP/R027129/1. As a low-cost alternative to noble metals, Cu plays an important role in industrial catalysis, such as water-gas shift reaction, methanol or ethanol oxidation, hydrogenation of oils, CO oxidation, among many others. An important step in optimizing Cu catalyst performance is control of nanoparticles size, distribution, and the interface with the support. While proton conducting perovskites can enhance the metal catalytic activity when acting as the support, there has been limited investigation of in situ growth of Cu metal nanoparticles from the proton conductors and its catalytic performance. Here, Cu nanoparticles are tracked exsolved from an A-site-deficient proton-conducting barium cerate-zirconate using scanning electron microscopy, revealing a continuous phase change during exsolution as a function of reduction temperature. Combined with the phase diagram and cell parameter change during reduction, a new exsolution mechanism is proposed for the first time which provides insight into tailoring metal particles interfaces at proton conducting oxide surfaces. Furthermore, the catalytic behavior in the CO oxidation reaction is explored and, it is observed that these new nanostructures can rival state of the art catalysts over long term operation. Publisher PDF

ZnGa2O4 reduced at high temperature led to the formation of anti-site defects, which resulted in high electrical conductivity and enabled it to obtain excellent electrochemical performance as a SOFC anode.

YT, YW, and FC gratefully acknowledge the Research Grant Council of Hong Kong for support through the projects 16206019 and 16201820 as well as the Hong Kong Scholar Program (XJ2021048). This work was supported in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone (HZQB-KCZYB-2020083). We gratefully appreciate the financial support from the National Key Research & Development Project (2020YFB1506304, 2017YFE0129300), National Natural Science Foundation of China (52172199, 52072135, 52002121), Fundamental Research Funds for the Central Universities (2021QN1111), the Open Project of Key Laboratory of Green Chemical Engineering Process of Ministry of Education (GCP202118), the Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization (2020KF04), and the Open Sharing Fund for the Large-scale Instruments and Equipment of China University of Mining and Technology (CUMT), the Analytical and Testing Centre of Huazhong University of Science and Technology are all appreciated for their assistance with sample characterization. Symmetric solid oxide cells (SSOCs) have attracted enormous attention in research and development because of their simple cell configuration and low fabrication costs. However, their development is limited by their electrocatalytic activity and stability of the electrode materials used. Herein, we report a novel perovskite oxide electrode Pr0.5Ba0.5Fe0.8Ni0.2O3−δ (PBFN) as a highly effective SSOC electrode material. The results demonstrate that PBFN has outstanding electrocatalytic potential for the oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction, and hydrogen oxidation reaction. After H2 treatment, its structure changes from single to double perovskite and is accompanied by Fe–Ni alloy nanoparticle exsolution. Compared with PBFN, the SSOCs with reduced PBFN qualities show improved electrochemical performance. A reduced PBFN-based device has a higher power density (0.201 W cm−2vs. 0.151 W cm−2 for H2 as a fuel at 750 °C) and an electrolysis current density (0.524 A cm−2vs. 0.353 A cm−2 for the electrolysis of pure CO2 at 750 °C @ 2 V) in comparison to the PBFN approach as is the case with other symmetric cell results. Thus, the reduced PBFN-based device shows favorable stability for both power density and electrolysis modes. These results suggest that phase transition and nanoparticle exsolution is a promising strategy for high performance SSOCs. Postprint

Electrochemical and catalytic conversion to and from ammonia is strongly enhanced by appropriate choice of hydrogen conducting electrolyte or substrate. Here we explore both protonic and hydride ionic conductors in relation to ammonia conversions. Protonic conductors tend to require too high a temperature to achieve sufficient hydrogen flux for ammonia synthesis as thermal decomposition competes stromgly. Coversely protonic conductors are well suited to direct ammonia fuel cell use. Hydride ions can be very mobile and are strongly reducing. Alakaline hydride lattices can exhibit facile H and N mobility and exchange and offer a very promising basis for ammonia conversion and synthesis. Publisher PDF

Funding: The authors thank the National Key Research and Development Program of China (no. 2021YFA0718900). They also thank the EPSRC for a Critical Mass project EP/R023522/1 and Electron Microscopy provision EP/R023751/1, EP/L017008/1; they also appreciate the support from National Research Foundation of Korea (NRF) grant funded by Korea government (MSIT) (no. 2021R1A2C2092130). Min acknowledges support from China Scholarship Council (no. 201706070126). Metal nanoparticles support materials play a crucial role in many fields, including energy conversion/storage, catalysis and photochemistry. Here, the exsolution is reported as an in situ method to fabricate metal nanoparticles supported on perovskite (La0.52Ca0.28Ni0.06Ti0.94O3) powder and fiber materials. Significantly decreased polarisation resistance can be achieved by applying electrochemical switching within 3 min on the fiber electrode fuel cell to facilitate the exsolution. The fuel cell activated by electrochemical switching under wet hydrogen shows a promising performance with a maximum output power density of about 380 mW cm−2 at 900 °C in hydrogen. The phase-field model shows that the exsolution under extreme low oxygen partial pressure induced by electrochemical switching performs faster nucleation than the chemical-reduced case. This work provides a further understanding of electrochemically driven exsolution with fiber structure platform and simulation with phase-field models. Publisher PDF

Funding: The authors thank the OxEon Corporation for supporting this work. The authors gratefully acknowledge the financial support from the Research Grants Council of Hong Kong (RGC Ref Nos. 16 201 820 and 16 206 019). This work was supported in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone (HZQB-KCZYB-2020083). We acknowledge the National Key Research and Development, Program of China (2017YFA0700102), Natural Science Foundation of China (91 845 202) and Strategic Priority Research Program of Chinese Academy of Sciences (XDB2000000). The authors acknowledge the financial support from the National Key R&D Program of China (2022YFB4004000). The authors gratefully acknowledge financial support from Department of Energy (DOE) Grant # DE-SC0016965, and DOE Grant # DE-FE0031986, which equally supported the authors in writing this review. This work has been carried out within the ViSEP program (733.000.006) funded jointly by the Netherlands Organization for Scientific Research (N.W.O.) and Shell. Research supported as part of the hydrogen in energy and information sciences, an Energy Frontier Research Center funded by the U.S. DOE, Office of Science, Basic Energy Sciences, under Award #DE-SC0023450. In addition, Y K acknowledges funding from the U.S. Army Research Office through Grant No. W911NF-22-1-0273. The project that gave rise to these results received the support of a fellowship from ‘la Caixa’ Foundation (ID 100 010 434). The fellowship code is LCF/BQ/PI20/11760015. This work was funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme, Grant Agreement No. 755744/ERC—Starting Grant TUCAS. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III, and the authors would like to thank Henrik Jeppesen for assistance in using beamline P02.1. Beamtime was allocated for proposal I-20211526 EC. The author is grateful for the financial support from the UK Catalysis Hub funded by EPSRC Grant reference EP/R027129/1. The authors wish to thank EPSRC for funding via Grant EP/R023921/1, the Henry Royce Institute (EP/X527257/1), the Royal Society of Chemistry (E22-6433572226) and The Royal Society (RGS\R2\222062). ISM acknowledges funding from the Royal Academy of Engineering through a Chair in Emerging Technologies Award entitled “Engineering Chemical Reactor Technologies for a Low-Carbon Energy Future” (Grant CiET1819\2\57). We thank the National Natural Science Foundation of China (Grant Nos. 51972233, 52172225 and 51825204), Natural Science Foundation of Shanghai (Grant No. 19ZR1459200), Science and Technology Commission of Shanghai Municipality (Grant No. 19DZ2271500) and the Fundamental Research Funds for the Central Universities for funding. Over the last decade, exsolution has emerged as a powerful new method for decorating oxide supports with uniformly dispersed nanoparticles for energy and catalytic applications. Due to their exceptional anchorage, resilience to various degradation mechanisms, as well as numerous ways in which they can be produced, transformed and applied, exsolved nanoparticles have set new standards for nanoparticles in terms of activity, durability and functionality. In conjunction with multifunctional supports such as perovskite oxides, exsolution becomes a powerful platform for the design of advanced energy materials. In the following sections, we review the current status of the exsolution approach, seeking to facilitate transfer of ideas between different fields of application. We also explore future directions of research, particularly noting the multi-scale development required to take the concept forward, from fundamentals through operando studies to pilot scale demonstrations. Postprint Publisher PDF

Ammonia is now being widely considered as a carrier for low carbon hydrogen due to its favourable physical properties and the existing infrastructure for its transport, storage and distribution. The direct utilisation of ammonia in Protonic Ceramic Fuel Cells (PCFCs) has the advantages of ammonia cracking activity and avoiding mixing of ammonia with generated steam. Here we seek to demonstrate a low-carbon electrical power generation system based on a PCFC fueled by ammonia for port and maritime applications. The performance of a 36 cm2 tubular cell with a proton conductive BaCe0.7Zr0.1Y0.16Zn0.04O3−δ (BCZYZ) electrolyte, composite Ni/BaCe0.7Zr0.1Y0.16Zn0.04O3−δ (Ni/BCZYZ) fuel electrode and La0.8Sr0.2Co0.5Fe0.5O3−δ/BaCe0.7Zr0.1Y0.16Zn0.04O3−δ LSCF/BCZYZ air electrode has been investigated using pure ammonia fuel. The tested cell generated up to 8.5 W with a maximum power density of 0.236 W cm−2 at 750 °C. The cell was operated in pure NH3, repeatedly characterised using I–V and EIS techniques, and tested under load to generate current for more than 140 h, with a fairly stable performance at a current above 8 A. Publisher PDF

The authors AA and NR would like to thank Universiti Brunei Darussalam for providing a UGS scholarship to perform this research. This work was supported by the UBD CRG project: UBD/OVACRI/CRGWG(006)/161201. Protonic ceramic fuel cells (PCFCs) have become the most efficient, clean and cost-effective electrochemical energy conversion devices in recent years. While significant progress has been made in developing proton conducting electrolyte materials, mechanical strength and durability still need to be improved for efficient applications. We report that adding 5 mol% Zn to the Y-doped barium cerate-zirconate perovskite electrolyte material can significantly improve the sintering properties, mechanical strength, durability and performance. Using same proton conducting material in anodes, electrolytes and cathodes to make a strong structural backbone shows clear advantages in mechanical strength over other arrangements with different materials. Rietveld analysis of the X-ray and neutron diffraction data of BaCe0.7Zr0.1Y0.15Zn0.05O3−δ (BCZYZn05) revealed a pure orthorhombic structure belonging to the Pbnm space group. Structural and electrochemical analyses indicate highly dense and high proton conductivity at intermediate temperature (400–700 °C). The anode-supported single cell, NiO-BCZYZn05|BCZYZn05|BSCF-BCZYZn05, demonstrates a peak power density of 872 mW cm−2 at 700 °C which is one of the highest power density in an all-protonic solid oxide fuel cell. This observation represents an important step towards commercially viable SOFC technology. Publisher PDF

Funding: UK Engineering and Physical Sciences Research Council (Grant Number(s): EP/R023522/1, EP/R023751/1, EP/L017008/1). Active bi-metallic nanoparticles are of key importance in catalysis and renewable energy. Here, the in situ formation of bi-metallic nanoparticles is investigated by exsolution on 200 nm diameter perovskite fibers. The B-site co-doped perovskite fibers display a high degree of exsolution, decorated with NiCo or Ni3Fe bi-metallic nanoparticles with average diameter about 29 and 35 nm, respectively. The perovskite fibers are utilized as cathode materials in pure CO2 electrolysis cells due to their redox stability in the CO/CO2 atmosphere. After in situ electrochemical switching, the nanoparticles exsolved from the perovskite fiber demonstrate an enhanced performance in pure CO2 electrolysis. At 900 °C, the current density of solid oxide electrolysis cell (SOEC) with 200 µm YSZ electrolyte supported NiFe doped perovskite fiber anode reaches 0.75 Acm−2 at 1.6 V superior to the NiCo doped perovskite fiber anode (about 1.5 times) in pure CO2. According to DFT calculations (PBE-D3 level) the superior CO2 conversion on NiFe compared to NiCo bi-metallic species is related to an enhanced driving force for C-O cleavage under formation of CO chemisorbed on the nanoparticle and a reduced binding energy of CO required to release this product. Publisher PDF

Funding: Authors would like to thank the ISIS Facility Development Studentship for funding this work. Additionally, I would like to thank ISIS Neutron and Muon Source for providing the beam time to collect all the scattering data presented in this paper. Finally, I would like to thank the Crockett Scholarship for supporting my studies. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) license to any Accepted Author Manuscript version arising. Ionic conductivity is a phenomenon of great interest, not least because of its application in advanced electrochemical devices such as batteries and fuel cells. While lithium, sodium, and oxide fast ion conductors have been the subjects of much study, the advent of hydride (H–) ion fast conductors opens up new windows in the understanding of fast ion conduction due to the fundamental simplicity of the H– ion consisting of just two electrons and one proton. Here we probe the nature of fast ion conduction in the hydride ion conductor, barium hydride (BaH2). Unusually for a fast ion conductor, this material has a structure based upon a close-packed hexagonal lattice, with important analogues such as BaF2 and Li2S. We elucidate how the structure of the high temperature phase of BaH2 results in a disordered hydride sublattice. Furthermore, using novel combined quasi-elastic neutron scattering (QENS) and electrochemical impedance spectroscopy (EIS) we show how the high energy ions interact to create a concerted migration that results in macroscopic superionic conductivity via an interstitialcy mechanism. Publisher PDF

The research was supported by EPSRC (Award Nos. EP/R023522/1, EP/R023603/1, EP/R023921/1, EP/R023638/1, EP/R008841/1, and EP/V055232/1) and financial support from the UK Catalysis Hub funded by EPSRC Grant reference EP/R027129/1. J.W. and S.C.P. gratefully acknowledge support from the EPSRC (EP/P007821/1) and also thank the U.K. ARCHER HPC facility and the THOMAS HPC (the UK Materials and Molecular Modelling Hub, partially funded by EPSRC EP/P020194) for providing computation resources, via the membership of the UK's HEC Materials Chemistry Consortium (funded by the EPSRC Grant Nos. EP/L000202, EP/709 P007821/1, EP/R029431, and EP/T022213). High‐performance nanoparticle platforms can drive catalysis progress to new horizons, delivering environmental and energy targets. Nanoparticle exsolution offers unprecedented opportunities that are limited by current demanding process conditions. Unraveling new exsolution pathways, particularly at low‐temperatures, represents an important milestone that will enable improved sustainable synthetic route, more control of catalysis microstructure as well as new application opportunities. Herein it is demonstrated that plasma direct exsolution at room temperature represents just such a step change in the synthesis. Moreover, the factors that most affect the exsolution process are identified. It is shown that the surface defects produced initiate exsolution under a brief ion bombardment of an argon low‐pressure and low‐temperature plasma. This results in controlled nanoparticles with diameters ≈19–22 nm with very high number densities thus creating a highly active catalytic material for CO oxidation which rivals traditionally created exsolved samples. Publisher PDF

Cyanobacteria and their toxic secondary metabolites present challenges for water treatment globally. In this study we have assessed TiO

Funding: Faraday Institution (Grant Number(s): FIRG018), Diamond Light Source (Grant Number(s): SP14239), Engineering and Physical Sciences Research Council (Grant Number(s): EP/L017008/1, EP/R023751/1, EP/T019298/1), SPRing8 (Grant Number(s): 2021A1425). Sodium layered oxides showing oxygen redox activity are promising positive electrodes for sodium‑ion batteries (SIBs). However, structural degradation typically results in limited reversibility of the oxygen redox activity. Herein, the effect of Zn‑doping on the electrochemical properties of P3-type sodium manganese oxide, synthesised under air and oxygen is investigated for the first time. Air‑Na 0.67 Mn 0.9 Zn 0.1 O 2 and Oxy‑Na 0.67 Mn 0.9 Zn 0.1 O 2 exhibit stable cycling performance between 1.8 and 3.8 V, each maintaining 96% of their initial capacity after 30 cycles, where Mn 3+ /Mn 4+ redox dominates. Increasing the voltage range to 1.8‑4.3 V activates oxygen redox. For the material synthesised under air, oxygen redox activity is based on Zn, with limited reversibility. The additional transition metal vacancies in the material synthesised under oxygen result in enhanced oxygen redox reversibility with small voltage hysteresis. These results may assist the development of high‑capacity and structurally stable oxygen redox‑based materials for SIBs. Publisher PDF

We greatly appreciate the financial support from the National Key Research & Development Project (2020YFB1506304, 2017YFE0129300), National Natural Science Foundation of China (52072135), and China Scholarship Council (201806160178). The oxygen electrode with a fast oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and sufficient durability plays a pivotal role in reversible solid oxide cells (RSOCs). Here, we demonstrate a NdBa0.5Ca0.5Co1.5Fe0.5O5+δ@Gd0.1Ce0.9O2−δ (NBCCF@GDC) composite oxygen electrode via a one-pot method for exhibiting strong coherency, which result in boosting the electrochemical performance of RSOCs. The NBCCF@GDC electrode yields a very low polarization resistance (0.106 Ω-cm2 at 800 °C), high electrolysis current density (1.45 A cm–2 with 70 vol % absolute humidity at 1.3 V), and high power density (∼1.3 W cm–2 at 800 °C) and shows excellent reversibility and stability. Notably, strong coherency in these NBCCF@GDC composite materials was successfully revealed by HT-XRD, XPS, STEM, and EELS. The phase contiguity and interfacial coherence between NBCCF and GDC increase the Co oxidation state and the number of active sites, which enhanced the electrocatalytic activity for perovskites. Overall, this work demonstrates a highly desirable strategy for the production of functionalized electrodes for next-generation reversible solid oxide cells. Postprint

The authors would like to thank the Petroleum Technology Development Fund (Nigeria) for funding this research and University of St Andrews (Scotland, UK) for the opportunity to carry out the research. Environmental problems associated with the use of fossil fuels and increase in energy demands due to rise in population and rapid industrialisation, are the driving forces for energy. Catalytic conversion of biomass to renewable energies is among the promising approaches to materialize the above. This requires development of robust catalysts to suppress deactivation due to carbon deposition and agglomeration. In this work, surface properties and chemistry such as exsolution of B-site metal catalyst nanoparticles, particle size and distribution, as well as catalyst-support interactions were tailored through the use of alkaline dopants to enhance catalytic behaviour in valorisation of glycerol. The incorporation of alkaline metals into the lattice of an A-site deficient perovskite modified the surface basic properties and morphology with a consequent robust catalyst-support interaction. This resulted in promising catalytic behaviour of the materials where hydrogen selectivity of over 30% and CO selectivity of over 60% were observed. The catalyst ability to reduce fouling of the catalyst surface as a result of carbon deposition during operation was also profound due to the robust catalyst-support interaction occurring at the exsolved nanoparticles due to their socketing and the synergy between the dopant metals in the alloy in perovskite catalyst systems. In particular, one of the designed systems, La0.4Sr0.2Ca0.3Ni0.1Ti0.9O3±δ, displayed almost 100% resistance to carbon deposition. Therefore, lattice rearrangement using exsolution and choice of suitable dopant could be tailored to improve catalytic performance. Publisher PDF

A critical new research direction in solid oxide cells (SOCs) relates to balancing power grid or integrating energy interconnection with heat-electricity-gas simply by operating under different modes including solid oxide fuel cell and electrolyser cell. The rational design of robust and high-performance materials for SOCs is urgent for high conversion/energy efficiencies. Iron is highly earth abundant and offers suitably flexible redox chemistry to address such operational modes. Iron-based oxide materials for SOCs are widely investigated because of the low cost and, but more importantly, the appropriate valence stability of the Fe-O bond, which affords good redox activity across a wide range of electrode functions. This review describes the progress in iron-based materials for SOCs, especially the recent applications in electrode materials or catalysts. The stable structure of the ferrite oxide allows and important platform for improved performance via substitution of Fe to deliver high-performance fuel electrodes of an SOC with H2/H2O or carbonaceous fuel/feedstock. Furthermore, we discuss nano-sized Fe0 metal or alloys on oxide electrode via infiltration and in situ exsolution aiming to fabricate high active electrocatalysts. The advances of ferrite oxide-based oxygen electrode are also discussed in terms of thermal expansion, structural stability and electrocatalysis before the development of symmetrical and reversible SOCs based on ferrite oxides are classified and summarized. Thereby, the challenges and future prospects are discussed.

Cyanobacteria and their toxins are a threat to drinking water safety as increasingly cyanobacterial blooms (mass occurrences) occur in lakes and reservoirs all over the world. Photocatalytic removal of cyanotoxins by solar light active catalysts is a promising way to purify water at relatively low cost compared to modifying existing infrastructure. We have established a facile and low-cost method to obtain TiO

This work was supported by the NSFC (Grants 51702264 and 41371275) and National Key Research and Development Program of China (Grant 2018FYD0200701) and research funding for central universities (Grant XDJK2020B066). B.L. acknowledges the Chongqing Graduate Scientific Research Innovation Project (Grant CYS20114). C.N. is also thankful for the Chongqing Bayu Young Scholar award from the Chongqing Teaching Committee. Employment of identical oxides for the cathode and anode in a symmetrical solid oxide fuel cell (SSOFC) is beneficial for decreasing the fabrication costs of a robust cell. Ce doping on the A site of SrFeO3 increased the structural stability in a reducing atmosphere, but ceria was found to exsolve from the perovskite during the cooling process in the air if the doping level reached 20 atom %. The additional doping of 5 atom % Ru in Sr0.8Ce0.2FeO3 on the Fe site could prevent the ceria segregation in air and induce the surface decomposition under fuel conditions for the formation of nanoscale SrO, CeO2, and Ru0. The SSOFC with Ce/Ru codoped SrFeO3 on a Sr- and Mg-doped LaGaO3 electrolyte showed a small Rp value (0.12 Ω cm2) when H2 and ambient air were used as fuel and oxidant, respectively. The peak power densities of 846 and 310 mW cm–2 were achieved at 800°C using H2 and C3H8 as fuel, respectively. The excellent coke resistance of the anode could be related to the simultaneous in situ exsolution of CeO2, SrO, and Ru0 nanoparticles. Postprint Postprint

Authors thank the Petroleum Technology Development Fund (PTDF), Nigeria for funding this research and the University of St Andrews, Scotland UK for the consideration to work with them and to use their facilities. The effects of catalyst loading, calcination and reaction temperatures on the structural properties and catalytic behavior of Ni/γ-Al2O3 catalyst system in relation to steam reforming of glycerol and catalyst deactivation were investigated. The results showed that catalyst loading, reaction and calcination temperatures had a profound influence on the structure and catalytic activity in glycerol conversion. Use of high calcination temperature (900-1000 °C) led to phase transformation of the active Ni/Al2O3 to less active spinel specie NiAl2O4 that resulted in a successive change of texture and color. The particle size growth and phase change at this temperature were responsible for the catalyst deactivation and low performance especially among the catalyst calcined at high temperatures. Conversely, at low reaction temperatures, catalyst surfaces were marred by carbon deposition. Whilethe polymeric carbon deposited at metal-support interface was associated with low reaction temperatures, high reaction temperatures were characterized predominantly by both amorphous carbon deposited on the active metal surface and polymeric or graphitic carbon deposited at metal-support interface respectively. Calcination temperature showed no significant influence on the location and type of coke deposited on the catalyst surface. Hence, catalyst loading, calcination and reaction temperatures could be tailored to enhance structural and catalytic properties and guard against catalyst deactivation. Publisher PDF

In this contribution, a reversible Solid Oxide Cell based on perovskites was developed. La0.6Sr0.4Ga0.3Fe0.7O3 (LSGF) was chosen as electrode and deposited onto La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) electrolyte. The cell was investigated from the morphological (SEM) and compatibility (XRD) point of view. Electrochemical investigation confirmed that the cell can operate in fuel cell and in electrolyser modes. Impregnation with CGO and Pd allowed a 15 times increment of the power density (until limit is the cell architecture). The same cell with an impregnated negative electrode was then tested in steam electrolysis mode in a non-reducing environment. The overall performance is slightly lower than state-of-the-art materials and comparable with similar perovskites, and in general is fair considering the needed cell optimization (i.e an anode supported configuration is necessary). The cell (impregnated and not) activates at 0.7 V. Obtained data suggest thus LSGF/LSGM/LSGF cell, is promising as reversible SOC for intermediate temperature. Postprint

The authors are highly thankful for the financial support of Higher Education Commission (HEC) Pakistan through the equipment/research grants (6976/Federal/NRPU/R&D/HEC/2017), (20-3071/NRPU/R&D/HEC/13). Author ZS acknowledges HEC for indigenous PhD Fellowship Phase-II, Batch-II, 2013, PIN 213-66018-2PS2-127 and International Research Support Initiative Programme (IRSIP). Author LKJ acknowledges support from a Marie Skłodowska-Curie Individual Fellowship (European Commission) (MCIF: No. 745776). This work demonstrates a route to making mixed halide perovskite powders at room temperature by the anti-solvent-assisted crystallization method. Although, mixed halide CH3NH3PbBr3−xClx perovskites have been prepared by different methods, however, to the best of our knowledge the anti-solvent-assisted crystallization method is employed here for the first time to prepare mixed halide CH3NH3PbBr3−xClx perovskite powders. Solution-processed methyl ammonium lead tribromide CH3NH3PbBr3 (x = 0) and different amounts of chloride (Cl) containing mixed halide perovskites (CH3NH3PbBr3−xClx) were prepared for compositions of x = 0.5, 1, 1.25, 1.75. It reveals that bulk CH3NH3PbBr3−xClx samples are highly crystalline and exists in pure single cubic phase with an increased tolerance factor as compared to pure CH3NH3PbBr3. The CH3NH3PbBr3 perovskite has space-group Pm-3 m and a cell parameter of 5.930 Å (volume = 206 Å). The synthesis route adopted here gives access to hybrid perovskites powders with high Cl content and hence enables the band gap to be precisely tuned over a range from 2.26 to 2.49 eV. The powder samples display the subtle shifts in the emission spectra and the photoluminescence kinetics exhibits a decrease in average lifetime by increasing the Cl contents due to the presence of trap states in the structures that encourage non-radiative recombination of charge carrier. Conventionally, the CH3NH3PbBr3-based inverted solar cell architecture is prepared via mixing of the CH3NH3Br and PbBr2 precursors. In contrast, herein, the precursor solutions are directly prepared from the CH3NH3PbBr3 powder and the active layer of the inverted perovskite solar cells are then spin coated using this solution. The high Voc value of the fabricated solar cells potentially makes it a promising candidate for tandem photovoltaic, photocatalytic water splitting, and semi-transparent photovoltaic applications. Postprint Postprint

The search for new functional materials that combine high stability and efficiency with reasonable cost and ease of synthesis is critical for their use in renewable energy applications. Specifically in catalysis, nanoparticles, with their high surface-to-volume ratio, can overcome the cost implications associated with otherwise having to use large amounts of noble metals. However, commercialized materials, that is, catalytic nanoparticles deposited on oxide supports, often suffer from loss of activity because of coarsening and carbon deposition during operation. Exsolution has proven to be an interesting strategy to overcome such issues. Here, the controlled emergence, or exsolution, of faceted iridium nanoparticles from a doped SrTiO3 perovskite is reported and their growth preliminary probed by in situ electron microscopy. Upon reduction of SrIr0.005Ti0.995O3, the generated nanoparticles show embedding into the oxide support, therefore preventing agglomeration and subsequent catalyst degradation. The advantages of this approach are the extremely low noble metal amount employed (∼0.5% weight) and the catalytic activity reported during CO oxidation tests, where the performance of the exsolved SrIr0.005Ti0.995O3 is compared to the activity of a commercial catalyst with 1% loading (1% Ir/Al2O3). The high activity obtained with such low doping shows the possibility of scaling up this new catalyst, reducing the high cost associated with iridium-based materials. Postprint Postprint

Materials that display strong capabilities for lithium insertion without significant change in unit cell size on cycling are of considerable importance for electrochemical applications. Here, we present V2O3(SO4)2 as a host for lithium-ion batteries. Electrochemically, 2.0 Li+ ions can be inserted, giving Li2V2O3(SO4)2 with an oxidation state of V4+, as determined by X-ray absorption spectroscopy. The capacity of V2O3(SO4)2 can be increased from 157 mA h g−1 to 313 mA h g−1 with the insertion of two additional Li+ ions which would drastically improve the energy density of this material, but this would be over a wider potential range. Chemical lithiation using n-butyllithium was performed and characterisation using a range of techniques showed that a composition of Li4V2O3(SO4)2 can be obtained with an oxidation state of V3+. Structural studies of the lithiated materials by X-ray diffraction showed that up to 4.0 Li+ ions can be inserted into V2O3(SO4)2 whilst maintaining its framework structure.

L. D. gratefully acknowledges financial support from the Swedish Energy Agency (contract 2020-005246). Y.C. and D.O.S. are grateful to the Faraday Institution for funding the MICHAEL computing cluster hosted at University College London (UCL). Our membership of the UKs HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202, EP/R029431), this work used the ARCHER2 UK National Supercomputing Service(http://www.archer2.ac.uk). We are also grateful to the UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (EP/P020194/1 and EP/T022213/1). We are grateful to the Engineering and Physical Sciences Research Council (EPSRC) Light Element Facility Grant (EP/T019298/1) for funding the acquisition of the Raman spectrometer. EF is grateful for an EaStCHEM studentship. This work was supported by the Faraday Institution (grant number FIRG018). Anion redox reactions offer a means of enhancing the capacity of layered sodium transition metal oxide positive electrode materials. However, oxygen redox reactions typically show limited reversibility and irreversible structural changes upon cycling, resulting in rapid capacity loss. Here, the Ti substituted Na4/7[□1/7Ti1/7Mn5/7]O2 (where □ represents a transition metal vacancy) is presented as a positive electrode material for sodium ion batteries. Na4/7[□1/7Ti1/7Mn5/7]O2 delivers a reversible capacity of 167 mAh g -1 after 25 cycles at 10 mA g -1 within the voltage range of 1.6 – 4.4 V and presents enhanced stability compared with Na4/7[□1/7Mn6/7]O2 over the voltage range 3.0 – 4.4 V. The structural and electronic structural changes of this Ti4+ substituted phase are investigated by powder X-ray diffraction, X ray absorption spectroscopy, electron paramagnetic resonance and Raman spectroscopy, supported by density functional theory calculations. These results show that the Na4/7[□1/7Mn6/7]O2 structure is maintained between 3.0 – 4.4 V, and the presence of TiO6 octahedra in Na4/7[□1/7Ti1/7Mn5/7]O2 relieves structural distortions from Jahn Teller distorted Mn3+O6 between 1.6 – 4.4 V. Furthermore, Ti4+ substitution stabilises the adjacent O 2p orbitals and raises the ionicity of the Mn O bonds, increasing the operating potential of Na4/7[□1/7Ti1/7Mn5/7]O2. Thereby providing evidence that the improved electrochemical performance of Na4/7[□1/7Ti1/7Mn5/7]O2 can be attributed to Ti4+ substitution. This work provides insight and strategies for improving the structural stability and electrochemical performance of sodium layered oxides. Publisher PDF

Funding: Faraday Institution (Grant Number(s): FIRG018); Engineering and Physical Sciences Research Council (Grant Number(s): EP/T019298/1, EP/L017008/1, EP/R023751/1); Energimyndigheten (Grant Number(s): 2020-005249); Spring 8 (Grant Number(s): 2019B1604). Oxygen anion redox offers an effective strategy to enhance the energy density of layered oxide positive electrodes for sodium- and lithium-ion batteries. However, lattice oxygen loss and irreversible structural transformations over the first cycle may result in large voltage hysteresis, thereby impeding practical application. Herein, ribbon superstructure ordering of Li/transition-metal-ions was applied to suppress the voltage hysteresis combined with Ti-substitution to improve the cycling stability for P3-Na0.67Li0.2Ti0.15Mn0.65O2. When both cation and anion redox reactions are utilized, Na0.67Li0.2Ti0.15Mn0.65O2 delivers a reversible capacity of 172 mA h g−1 after 25 cycles at 10 mA g−1 between 1.6–4.4 V vs. Na+/Na. Ex-situ X-ray diffraction data reveal that the ribbon superstructure is retained with negligible unit cell volume expansion/contraction upon sodiation/desodiation. The performance as a positive electrode for Li-ion batteries was also evaluated and P3-Na0.67Li0.2Ti0.15Mn0.65O2 delivers a reversible capacity of 180 mA h g−1 after 25 cycles at 10 mA g−1 when cycled vs. Li+/Li between 2.0–4.8 V. Publisher PDF

Nanostructured one-dimensional multiwall-carbon nanotubes have a variety of advantageous properties including good electrical conductivity and mechanical strength, and thus have been widely investigated for use in lithium-ion battery electrodes as conductive and microstructural additives, though they also possess some electrochemical activity. Their application to sodium-ion batteries has been less extensively researched, and therefore a greater understanding of the electrochemical reaction with sodium, and effects of slurry composition and electrolyte formulation is warranted, especially as these are likely components in future Na-ion electrode formulations. Here, we report the fabrication of aqueous and organic multi-wall carbon nanotube (MWCNT) negative electrodes processed by ball milling. The binder of choice is noted to greatly affect the electrochemical performance, both in terms of capacity retention and rate capability over a range of current densities from 25 to 500 mA g−1. Switching from a carbonate- to diglyme-based electrolyte considerably improves initial coulombic efficiencies (∼10%–60%), attributed to less extensive formation of solid electrolyte interphase, and enables a reversible mechanism with capacities up to 150 mAh g−1 over 100 cycles depending upon the binder used. Ex-situ characterization of the discharged and cycled carbon nanotubes by powder x-ray diffraction, transmission electron microscopy and Raman spectroscopy provide an insight into how MWCNTs undergo sodiation and demonstrate a partially reversible structural transformation during cycling when using the diglyme-based electrolyte. This work lays the foundation for a better understanding of these versatile materials, especially when used in the most promising alternative energy storage technology to lithium ion.

The authors would like to thank the Engineering and Physical Sciences Research Council (EPSRC) [EP/P029280/1], the Coordination for the Improvement of Higher Education Personnel - CAPES [PROEX 20/2016 and PrInt 88887.311806/2018–00], and the Brazilian National Research Council – CNPq [403116/2016–3 and 304164/2017–8] for funding this research. As per EPSRC requirement all data will be made publicly available via the Robert Gordon University's open access repository OpenAIR@RGU. Further, the first author also acknowledges the scholarship from the Brazilian National Research Council - CNPq. To date, the high cost of supplying UV irradiation has prevented the widespread application of UV photolysis and titanium dioxide based photocatalysis in removing undesirable organics in the water treatment sector. To overcome this problem, the use of UV-LEDs (365 nm) for photolysis and heterogeneous photocatalysis applying TiO2 coated glass beads under UV-LED illumination (365 nm) in a pilot scale reactor for the elimination of Microcystis aeruginosa PCC7813 and four microcystin analogues (MC-LR, -LY, -LW, -LF) with a view to deployment in drinking water reservoirs was investigated. UV-A (365 nm) photolysis was shown to be more effective than the UV/TiO2 photocatalytic system for the removal of Microcystis aeruginosa cells and microcystins. During photolysis, cell density significantly decreased over 5 days from an initial concentration of 5.8 × 106 cells mL−1 until few cells were left. Both intra- and extracellular microcystin concentrations were significantly reduced by 100 and 92 %, respectively, by day 5 of the UV treatment for all microcystin analogues. During UV/TiO2 treatment, there was great variability between replicates, making prediction of the effect on cyanobacterial cell and toxin behavior difficult. Postprint Postprint

Funding information: This work was supported by the Faraday Institution (Grant No. FIRG018). The authors gratefully acknowledge support from the Engineering and Physical Sciences Research Council (EPSRC), Grant Nos. EP/L017008/1, EP/R023751/1 and EP/T019298/1. Sodium layered oxides which display oxygen anion redox behaviour are considered promising positive electrodes for sodium-ion batteries because they offer increased specific capacities. However, they suffer from irreversible structural changes resulting in significant capacity loss and limited oxygen redox reversibility. Here the effect of Cu substitution on the electrochemical performance of P3-type sodium manganese oxide is examined by evaluating the structural and electronic structural evolution upon cycling, supported by density functional theory (DFT) calculations. Over the voltage range 1.8–3.8 V vs. Na/Na+, where the redox reactions of the transition metal ions contribute entirely towards the charge compensation mechanism, stable cycling performance is maintained, showing a capacity retention of 90% of the initial discharge capacity of 166 mA h g−1 after 40 cycles at 10 mA g−1. Over an extended voltage range of 1.8–4.3 V vs. Na/Na+, oxygen anion redox is invoked, with a voltage hysteresis of 110 mV and a greater initial discharge capacity of 195 mA h g−1 at 10 mA g−1 is reached. Ex-situ powder x-ray diffraction patterns reveal distortion of the P3 structure to P'3 after charge to 4.3 V, and then transformation to O'3 upon discharge to 1.8 V, which contributes towards the capacity fade observed between the voltage range 1.8–4.3 V. DFT with projected density of states calculations reveal a strong covalency between the copper and oxygen atoms which facilitate both the cationic and anionic redox reactions in P3-type Na0.67Mn0.9Cu0.1O2. Publisher PDF

Thanks to large efficiency and ability to work in both fuel cell and electrolysis mode Solid Oxide Cells (SOCs) could become a vital technology in the transition to the carbon-neutral energy sector based on hydrogen. However, large cost and low durability constrain their full-scale commercialization. These challenges are tackled in the present work. Tubular cells are produced by a simple and inexpensive method, suitable for mass production. The cells showed excellent activity, stability and redox resistance due to tubular design and fully ceramic electrodes. Thermal shock resistance testing showed that the cell is resistant to rapid temperature changes. A thick supporting layer of the porous backbone was cast first, and a thin layer of electrolyte over it. After rolling into a tubular shape, the assembly was co-sintered and impregnated with functional perovskite materials. Co-casting allowed to achieve a strong interface and reduce the thickness of electrolyte. The impregnation gave the possibility to deposit a perovskite in temperature much lower than in state-of-art methods, preventing the undesirable reaction with zirconia electrolyte and reducing their densification, producing more active spatial microstructures with large surface area. Moreover, such electrodes are more thermally compatible with electrolyte as their bulk TEC is mainly controlled by the porous backbone made of the same material as the electrolyte. Yttria-stabilized zirconia (Zr0.92Y0.16O2.08, 8YSZ) is used as the electrolyte, for the fuel electrode nickel doped lanthanum calcium titanate (La0.43Ca0.37Ni0.06Ti0.94O3- γ, LCNT) was impregnated onto a porous 8YSZ backbone, while on the air electrode a lanthanum strontium ferrite (La0.8Sr0.2FeO3, LSF) was applied. These materials offer high activity and stability for a relatively low price. Electrochemical impedance spectroscopy (EIS), current-voltage (I-V) and potentiostatic measurements were carried out to characterize cell performance and cell’s stability during the test. The electrochemical testing showed improvement in the cell performances after electrochemical poling at high potential, due to facilitated LCNT reduction and exsolution of nickel nanoparticles. The cheap fabrication method, competitive performance, attracting redox stability and thermal shock resistance, braking the major limitation for SOFC applicability, making it even suitable to be used in portable applications.

This work was supported by EPSRC (EP/K022237/1, EP/M024938/1 and EP/R023638/1), the EPSRC Supergen SuperSolar Hub, the Department for Employment and Learning (DEL) of Northern Ireland Studentship, and by the New Energy and Industrial Technology Development Organization (NEDO). We observe the extraction of carriers excited between two types of bands in the perovskite oxide, Sr-deficient strontium niobate (Sr0.9NbO3). Sr0.9NbO3 exhibits metallic behaviour and high conductivity, whilst also displaying broad absorption across the ultraviolet, visible, and near-infrared spectral regions, making it an attractive material for solar energy conversion. Furthermore, the optoelectronic properties of strontium niobate can easily be tuned by varying the Sr fraction or through doping. Sr-deficient strontium niobate exhibits a split conduction band, which enables two types of optical transitions: intraband and interband. However, whether such carriers can be extracted from an unusual material as such remains unproven. In this report, we have overcome the immense challenge of photocarrier extraction by fabricating an extremely thin absorber layer of Sr0.9NbO3 nanoparticles. These findings open up great opportunities to harvest a very broad solar spectral absorption range with reduced recombination losses. Publisher PDF

Alternative and sustainable waste sources are receiving increasing attention as they can be used to produce biofuels with a low carbon footprint. Waste fish oil is one such example and can be considered an abundant and sustainable waste source to produce biodiesel. Ultimately this could lead to fishing communities having their own ‘off-grid’ source of fuel for boats and vehicles. At the industrial level, biodiesel is currently produced by homogeneous catalysis because of the high catalyst activity and selectivity. In contrast, heterogeneous catalysis offers several advantages such as improved reusability, reduced waste and lower processing costs. Here we investigate the phase evolution of two heterogeneous catalysts, CaO and a Ca3Al2O6:CaO (‘C3A:CaO’) composite, under in-situ conditions for biodiesel production from fish oil. A new reactor was designed to monitor the evolution of the crystalline catalyst during the reaction using synchrotron powder x-ray diffraction. The amount of calcium diglyceroxide (CaDG) began to increase rapidly after approximately 30 min, for both catalysts. This rapid increase in CaDG could be linked to ex-situ nuclear magnetic resonance studies which showed that the conversion of fish oil to biodiesel rapidly increased after 30 min. The key to the difference in activity of the two catalysts appears to be that the Ca3Al2O6:CaO composite maintains a high rate of CaDG formation for longer than CaO, although the initial formation rates and reaction kinetics are similar. The Ca for the CaDG mainly comes from the CaO phase. In addition, towards the end of the second test utilising the CaO catalyst (after 120 min), there is a rapid decrease in CaDG and a rapid increase in Ca(OH)2. This was not observed for the Ca3Al2O6:CaO catalyst and this is due to Ca3Al2O6 stabilising the CaO in the composite material. No additional calcium containing intermediate crystalline phases were observed during our in-situ experiment. Overall this specialised in-situ set-up has been shown to be suitable to monitor the phase evolution of heterogeneous crystalline catalysts during the triglycerides transesterification reaction, offering the opportunity to correlate the crystalline phases to activity, deactivation and stability.

The authors, A M Abdalla and S Hossain, are grateful to Suez Canal University and Universiti Brunei Darussalam and their collaborative for supporting this research work.