SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4277-1
Two-dimensional (2D) magnetic materials hold promise for next-generation spintronics, yet most exhibit Curie temperatures (Tc) far below room temperature, limiting practical applications. Here, we report the realization of room-temperature ferromagnetism in CuCrSe2 nanosheets via controlled anion removal achieved by post-synthetic vacuum annealing. Raw CuCrSe2 shows a low Tc of ~120 K, whereas annealed CuCrSe2 (A-CuCrSe2) nanosheets exhibit robust ferromagnetic ordering above 300 K. Structural and compositional analyses, including transmission electron microscopy, Raman spectroscopy, and X-ray absorption spectroscopy, confirm that A-CuCrSe2 retains the original layered crystal structure with an estimated Se vacancy concentration of approximately 10%. Magnetic measurements reveal room-temperature ferromagnetism in exfoliated nanosheets, corroborated by magnetic imaging and electric transport measurements. Anomalous Hall effect (AHE) measurements uncover the coexistence of two ferromagnetic phases within the same sample: one with low Tc (~120 K) and another with high Tc (>300 K), indicating spatially heterogeneous magnetic ordering driven by anion removal distribution. Density functional theory (DFT) calculations elucidate the microscopic mechanism, suggesting that Se vacancies modulate the magnetic exchange interactions, enhancing Tc. This work demonstrates that anion modulation is an effective intrinsic strategy to achieve room-temperature ferromagnetism in 2D materials, potentially advancing spintronic applications.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.3724/2097-213X.2025.JFCT.0034
Catalytic cracking of gasoline and diesel to light olefins is a pivotal route for high-value utilization of surplus fuels, typically employing zeolite catalysts. This study systematically investigates the effects of zeolite type and acidic properties on the catalytic cracking of dodecane, a diesel model compound, using SAPO-34, ZSM-5 with SiO2/Al2O3 ratios of 38, 85, and 200, and USY. Catalysts were characterized by XRD, SEM, N2 physisorption, NH3-TPD, and pyridine-FTIR, and evaluated in a fixed-bed reactor. Results demonstrate that zeolite type is the primary determinant of conversion and product distribution. SAPO-34, with 0.38 nm pores, achieved only 24.33% conversion and negligible BTX yield, with severe external coking. ZSM-5-38 and USY, with larger pores, achieved near-complete conversion; however, ZSM-5-38, possessing moderate acidity, yielded the highest light olefins (18.40%) and minimal coke (0.18%), while USY, with higher acidity, promoted hydrogen transfer and coking (12.90% coke). Within ZSM-5 series, lower acid site density (ZSM-5-200) proved optimal, achieving 97.79% conversion and a total light olefin yield of 41.93% (ethylene 11.11%, propylene 20.33%, butenes 10.49%) with low coke (0.43%). The study proposes reaction pathways and regulatory mechanisms, highlighting that zeolite type and acidity govern the relative rates of cracking, hydrogen transfer, oligomerization, aromatization, and coking, thereby dictating performance. These findings provide a rational basis for optimizing zeolite catalysts in commercial gasoline/diesel cracking processes.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4079-4
Utilization of ultrahigh-nickel LiNi_xCo_yMn_1-x-yO_2 (NCM) (x > 0.97) in Li-ion batteries can distinctively boost energy density through enhanced discharge capacity. However, capacity and thermal stability deteriorate as Ni content approaches the limit. Here, we propose a facile strategy by introducing high-valence tungsten (W) into ultrahigh-nickel polycrystalline LiNi_0.98Co_0.01Mn_0.01O_2 (PCNCM98). W-doped PCNCM98 (W-PCNCM98) exhibits refined, compactly stacked primary particles, whereas PCNCM98 shows equiaxial, non-uniform larger particles. The refined microstructure enhances mechanical strength: average particle hardness of W-PCNCM98 is 104 MPa, 1.5 times higher than PCNCM98 (68 MPa). This improved mechanical property suppresses lattice volume changes and relieves microcrack formation from H2–H3 phase transition. Consequently, cycling performance in pouch-type full cells is significantly enhanced, with capacity retention of 73% after 2000 cycles at 1 C and 25 °C, 54% higher than PCNCM98. Enhanced structural stability and strong electron affinity of W6+ also improve thermal stability: exothermic peak for W-PCNCM98 is postponed to 203 °C with heat generation of 1287 J g−1, versus 190 °C and 1528 J g−1 for PCNCM98. This high-valent doping strategy stabilizes ultrahigh-nickel NCM cathodes, accelerating large-scale EV applications.