Introduction.
June 6 and June 7, 2022Xie Kui's research team from Fujian Institute of Structure of Matter, Chinese Academy of Sciencesrespectively in Nature Sustainability (nat.). sustain., if=19.346) and Angewandte Chemie International Edition (Angew.). chem. int. ed., if=15.336), namely, ".sustainable ammonia production enabled by membrane reactor"And".selective oxidative coupling of methane to ethylene in a solid oxide electrolyser based on porous single-crystalline ceo2 monoliths”。Below, a brief introduction to these two achievements is provided for you to learn and understand!
nat. sustain.: Membrane reactor for sustainable ammonia synthesis
The ammonia industry is critical to global food** through the economical mass production of fertilizers, and it allows the development of catalytic chemistries and technologies that use ammonia as a carbon-free energy carrier. While the Haber-Bosch technology (nitrohydrolysis by facilitating FE catalysts under harsh conditions) will continue to play a key role, its huge carbon footprint and energy consumption require more sustainable production methods, ideally in close proximity to environmental stress. Based on this,Xie Kui, researcher (corresponding author), Fujian Institute of Structure of Matter, Chinese Academy of Sciences, et alA conceptually different method is reported that utilizes the bipolar diffusion of electrons (E-) and nitrogen ions (N3-) in a nitrogen permeation membrane reactor to synthesize ammonia in green. First, nitrogen (N2) is chemically adsorbed, activated, and decomposed into nitrogen ions on one side, which is then transported through the airtight membrane to the surface on the other side by bipolar diffusion. On the surface, the transported nitrogen ions (N3-) react with hydrogen to form ammonia inside the membrane reactor. The effective activation of N2 was confirmed by 14N 15N isotope tracer experiments. Among them, at 450, the N2 permeability flux is as high as 31 10-2 ml cm-2 h-1 with an ammonia yield of 29 μmol cm-2 h-1。The reaction of the osmotic N3- ion with H2 produces 0The high ammonia concentration of 097 vol% is close to the thermodynamic equilibrium limit (01 vol%）。In addition, the membrane reactor has the advantages of long life, low cost and scalability. Energy efficiency can be further improved by utilizing available waste heat streams from nuclear power plants and industry, while renewable energy sources such as wind, solar, and geothermal energy can be converted into heat to keep membrane reactors running. This work not only creates a more environmentally friendly pathway for atmospheric pressure ammonia synthesis, but also proposes a new membrane reactor design that can find applications in other fields.
*Courier. 
Figure 1Nitrogen permeation in a nitride membrane reactor
Figure 2Measurement of ammonia synthesis in membrane reactors
Figure 3Reactors with different nitride membranes
Summary. In conclusion, the authors demonstrate a sustainable method for the synthesis of ammonia by nitrogen ion activation in a membrane reactor under ambient stress. The rate of formation of ammonia reaches 29 mol cm-2 h-1 with an ammonia content of 0 in the gas phase of 450097 vol%。Ammonia synthesis is confirmed by osmotic nitrogen, as confirmed by in situ FTIR and 15N2 isotope tracer experiments.
This work introduces a new method for the synthesis of ammonia using a nitrogen permeation membrane reactor under ambient pressure and demonstrates the great potential for ammonia synthesis at the practical application level. Due to the need for higher energy efficiency and more flexible small-scale distribution processes, nitrogen permeation membrane reactors can offer many advantages and expand the range of ammonia synthesis that is actually feasible under environmental stress. Ammonia synthesis in membrane reactors can utilize waste heat flows from industrial processes to maintain the required operating temperature at 400-450 and maximize energy efficiency compared to energy-intensive H-B technologies, while ambient stress significantly reduces energy input.
Article information. sustainable ammonia production enabled by membrane reactor.nat. sustain.,, doi: 10.1038/s41893-022-00908-6.
angew. chem. int. ed.: Selective oxidative coupling of methane and ethylene in a solid oxide electrolyzer based on porous single crystal CEO2 blocks
It is well known that the catalytic conversion of methane (CH4) to ethylene (C2H4) plays an important role in the light olefin industry. Based on this,Xie Kui, researcher (corresponding author), Fujian Institute of Structure of Matter, Chinese Academy of Sciences, et alElectrochemical conversion of CH4 to ethylene ethane (C2H4 C2H6) at the cathode and electrolysis of CO2 to CO at the cathode in solid oxide electrolysers (SOEs) have been reported. The authors constructed a well-defined interface to serve as a three-phase boundary by dissolving single-crystalline (SC) Ni nanoparticles (NI NPS) in porous single-crystal (PSC) cerium dioxide (CEO2) blocks, and designed the chemical state and flux of reactive oxygen species for anodizing CH4 by controlling voltage and temperature. Experimental tests have found unprecedented C2 selectivity (C2H4 and C2H6) and a C2 selectivity of 99 at a conversion rate of about 7% for CH45%。The electrolyzer exhibited excellent durability with no degradation in performance observed during 100 h of continuous operation. This work will open up a new avenue for the selective conversion of CH4 CO2 into useful chemicals, and the technology for building well-defined interfaces may find potential applications in other areas.
*Courier. 
Figure 1PSC CEO2 block with in situ dissolved SC Ni nanoparticles
Figure 2Catalytic mechanism of CH4 oxidation
Figure 3Catalytic mechanism of CO2 reduction
Figure 4Electrochemical properties of SOES
Summary. In conclusion, the authors demonstrate the selective conversion of CH4 to C2 product in an effective electrochemical process in SOE, where the conversion of CH4 at the anode is combined with the reduction of CO2 at the cathode. The precipitation of the well-defined active interface in the PSC CEO2 electrode not only improves the catalytic activity, but also improves the anti-coking and thermal stability. With a CH4 conversion rate of around 7%, an unprecedented 995% C2 selectivity. In addition, the good active interface shows high temperature stability and can last for 100 h. This work can open up a new avenue for the oxidation of CH4 in electrochemical processes, and the metal-oxide interface may provide a wide range of potential applications in other fields.
Article information. selective oxidative coupling of methane to ethylene in a solid oxide electrolyser based on porous single-crystalline ceo2 monoliths. angew. chem. int. ed.,, doi: 10.1002/anie.202207211.
About the corresponding author.
Researcher Xie Kui, researcher of Fujian Institute of Physical Structure, Chinese Academy of Sciences, doctoral supervisor, research team leader, etc.