CMP Journal 2025-01-20
Statistics
Nature: 1
Nature Materials: 2
Nature Physics: 1
Nature
Methane oxidation to ethanol by a molecular junction photocatalyst
Original Paper | Catalytic mechanisms | 2025-01-19 19:00 EST
Jijia Xie, Cong Fu, Matthew G. Quesne, Jian Guo, Chao Wang, Lunqiao Xiong, Christopher D. Windle, Srinivas Gadipelli, Zheng Xiao Guo, Weixin Huang, C. Richard A. Catlow, Junwang Tang
Methane, the major component of natural and shale gas, is a significant carbon source for chemical synthesis. The direct partial oxidation of methane to liquid oxygenates under mild conditions1-3 is an attractive pathway, but the molecule's inertness makes it challenging to achieve simultaneously high conversion and high selectivity towards a single target product. This difficulty is amplified when aiming for more valuable products that require C-C coupling4,5. While selective partial methane oxidation processes1-3,6-9 have thus typically generated C1 oxygenates6,7, recent reports have documented photocatalytic methane conversion to the C2 oxygenate ethanol with low conversions but good to high selectivities4,5,8-12. Here, we show that the intramolecular junction photocatalyst CTF-1 with alternating benzene and triazine motifs7,13 drives methane coupling and oxidation to ethanol with a high selectivity and much improved conversion. The heterojunction architecture not only enables efficient and long-lived separation of charges after their generation, but also preferential adsorption of H2O and O2 to the triazine and benzene units, respectively. This dual-site feature separates C-C coupling to form ethane intermediates from the sites where •OH radicals are formed and thereby avoids overoxidation. When loaded with Pt to boost performance further, the molecular heterojunction photocatalyst generates ethanol in a packed-bed flow reactor with improved conversion that results in an apparent quantum efficiency of 9.4%. We anticipate that further developing the "intramolecular junction" approach will deliver efficient and selective catalysts for C-C coupling, pertaining, but not limited, to methane conversion to C2+ chemicals.
Catalytic mechanisms, Natural gas, Photocatalysis
Nature Materials
Revitalizing interphase in all-solid-state Li metal batteries by electrophile reduction
Original Paper | Batteries | 2025-01-19 19:00 EST
Weiran Zhang, Zeyi Wang, Hongli Wan, Ai-Min Li, Yijie Liu, Sz-Chian Liou, Kai Zhang, Yuxun Ren, Chamithri Jayawardana, Brett L. Lucht, Chunsheng Wang
All-solid-state lithium metal batteries promise high levels of safety and energy density, but their practical realization is limited by low Li reversibility, limited cell loading and demand for high-temperature and high-pressure operation, stemming from solid-state electrolyte (SSE) low-voltage reduction and high-voltage decomposition, and from lithium dendrite growth. Here we concurrently address these challenges by reporting that a family of reductive electrophiles gain electrons and cations from metal-nucleophile materials (here a Li sulfide SSE) upon contact to undergo electrochemical reduction and form interphase layers (named solid reductive-electrophile interphase) on material surfaces. The solid reductive-electrophile interphase is electron blocking and lithiophobic, prevents SSE reduction, suppresses Li dendrites and supports high-voltage cathodes. Consequently, a reductive-electrophile-treated SSE exhibits high critical capacity and Li reversibility at the anode, and enables Li(1% Mg)/SSE/LiNi0.8Co0.15Al0.05O2 all-solid-state lithium metal batteries to achieve a high coulombic efficiency (>99.9%), long cycle life (~10,000 h) and high loading (>7 mAh cm-2) at 30 °C and 2.5 MPa. This concept also extends to cathodes of other materials (for example, metal oxides), boosting the high-nickel cathode's cycle life and expanding the operational voltage up to 4.5 V. Such solid reductive-electrophile interphase tailoring of material surfaces holds promise to accelerate all-solid-state lithium metal battery commercialization and offer solutions for a wide range of materials.
Batteries, Chemical physics
Bose-Einstein condensation of a two-magnon bound state in a spin-1 triangular lattice
Original Paper | Bose-Einstein condensates | 2025-01-19 19:00 EST
Jieming Sheng, Jia-Wei Mei, Le Wang, Xiaoyu Xu, Wenrui Jiang, Lei Xu, Han Ge, Nan Zhao, Tiantian Li, Andrea Candini, Bin Xi, Jize Zhao, Ying Fu, Jiong Yang, Yuanzhu Zhang, Giorgio Biasiol, Shanmin Wang, Jinlong Zhu, Ping Miao, Xin Tong, Dapeng Yu, Richard Mole, Yi Cui, Long Ma, Zhitao Zhang, Zhongwen Ouyang, Wei Tong, Andrey Podlesnyak, Ling Wang, Feng Ye, Dehong Yu, Weiqiang Yu, Liusuo Wu, Zhentao Wang
In ordered magnets, the elementary excitations are spin waves (magnons), which obey Bose-Einstein statistics. Similarly to Cooper pairs in superconductors, magnons can be paired into bound states under attractive interactions. The Zeeman coupling to a magnetic field is able to tune the particle density through a quantum critical point, beyond which a ‘hidden order' is predicted to exist. Here we report direct observation of the Bose-Einstein condensation of the two-magnon bound state in Na2BaNi(PO4)2. Comprehensive thermodynamic measurements confirmed the two-dimensional Bose-Einstein condensation quantum critical point at the saturation field. Inelastic neutron scattering experiments were performed to establish the microscopic model. An exact solution revealed stable two-magnon bound states that were further confirmed by electron spin resonance and nuclear magnetic resonance experiments, demonstrating that the quantum critical point is due to the pair condensation, and the phase below the saturation field is likely the long-sought-after spin nematic phase.
Bose-Einstein condensates, Magnetic properties and materials, Phase transitions and critical phenomena
Nature Physics
An electronic microemulsion phase emerging from a quantum crystal-to-liquid transition
Original Paper | Electronic properties and materials | 2025-01-19 19:00 EST
Jiho Sung, Jue Wang, Ilya Esterlis, Pavel A. Volkov, Giovanni Scuri, You Zhou, Elise Brutschea, Takashi Taniguchi, Kenji Watanabe, Yubo Yang, Miguel A. Morales, Shiwei Zhang, Andrew J. Millis, Mikhail D. Lukin, Philip Kim, Eugene Demler, Hongkun Park
Strongly interacting electronic systems often exhibit a complicated phase diagram that results from the competition between different quantum ground states. One feature of these phase diagrams is the emergence of microemulsion phases, where regions of different phases self-organize across multiple length scales. The experimental characterization of these microemulsions can pose considerable challenges, as the long-range Coulomb interaction microscopically mingles with the competing states. Here we observe the signatures of the microemulsion between an electronic Wigner crystal and an electron liquid in a MoSe2 monolayer using cryogenic reflectance and magneto-optical spectroscopy. We find that the transition into this microemulsion state is marked by anomalies in exciton reflectance, spin susceptibility and umklapp scattering, establishing it as a distinct phase of electronic matter.
Electronic properties and materials, Phase transitions and critical phenomena, Quantum fluids and solids