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Silica-supported nanostructured copper phyllosilicate: Boosting stability, capacity, and conductivity of Li-ion battery Si-based anodes
(2026-11-01)
Shajan, Minnu Gemini
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Chou, Feng Yuan
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Prasanseang, Warot
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Yimtrakarn, Trakarn
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Sooknoi, Tawan
Explosive demand for large-scale rechargeable batteries has driven the search for alternative electrode materials with higher energy density, lower toxicity, lower cost, and more natural abundance. Si-based materials, e.g., Si, SiO, SiO<inf>2</inf>, and silicates have emerged as promising choices, with extremely high capacities from most cost-effective and abundant sources. However, these compounds still suffer from major issues, such as extreme volume change, poor cycling stability, high manufacturing costs, and low conductivity. Herein, we have prepared low-cost porous nanosized silica-supported copper phyllosilicate, x CuPS/SiO<inf>2</inf>, with different Cu loadings and investigated them as anode material in Li cells. Due to the highly dispersed Cu species strongly interacted with nanosphere SiO<inf>2</inf> support matrix, 20CuPS/SiO<inf>2</inf> has been found to deliver a capacity as high as ∼3550 mAh g‒1 at 500 mA g‒1 with an impressive capacity retention of 99% upon conversion reactions with Li+, and a reversible capacity of 2216 mAh g‒1 at 5000 mA g‒1. These values are among the highest ever reported for Si-, silicate-, silica-, and copper oxide-based anodes. Various phases, i.e., CuO, Li<inf>4</inf>SiO<inf>4</inf>, SiO, Si, Li<inf>2</inf>O, Cu, and Li<inf>x</inf>Si, are formed in the SiO<inf>2</inf> nanodomain, as confirmed by various ex situ characterization techniques, and the redox mechanism has been proposed. The components, particularly Li<inf>4</inf>SiO<inf>4</inf>, Li<inf>2</inf>O, and SiO<inf>2</inf>, are shown to help buffer volumetric or structural changes induced by the redox processes. The nanosized composite and the in situ -formed metallic Cu play a crucial role in rapid charge-transfer kinetics. These synergistic effects ultimately result in an unprecedented electrochemical performance of x CuPS/SiO<inf>2</inf> observed in this work.
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Stabilized Pd Nanoparticles Encapsulated in MIL-101(Cr) for Chemoselective Hydrogenation of Polyunsaturated FAMEs
(2025-11-24)
Preedawichitkun, Yardthip
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Numwong, Natthida
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Chanlek, Narong
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Chung, Po Wen
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Kumar, Raju
Palladium nanoparticles (Pd NPs) were successfully encapsulated within the porous framework of MIL-101(Cr) via a double solvent method to produce highly dispersed and stable catalysts for the chemoselective hydrogenation of polyunsaturated fatty acid methyl esters (FAMEs). Pd loadings ranging from 0.5 to 1.5 wt.% were systematically studied to elucidate the effects of nanoparticle size, dispersion, and hydrogen activation behavior on catalytic performance. The 0.8Pd/MIL-101(Cr) catalyst exhibited the highest turnover frequency (TOF ∼9,700 h−1) and superior selectivity (>90%) toward monounsaturated products (C18:1), attributed to optimal Pd dispersion. In contrast, the 0.5Pd/MIL-101(Cr) showed an induction period under low H<inf>2</inf> partial pressure, indicating limitations in hydride accommodation, while the 1.5Pd/MIL-101(Cr) suffered from Pd aggregation, resulting in a reduced intrinsic activity. Product selectivity was primarily governed by overall conversion: C18:1 was favored at low conversions, whereas C18:0 formation increased at higher conversions due to secondary hydrogenation. The catalysts demonstrated excellent stability and recyclability over multiple cycles without detectable Pd leaching or structural degradation. These findings establish MIL-101(Cr) as a robust and tunable platform for dispersing Pd NPs and highlight the potential of Pd/MIL-101(Cr) catalysts for efficient, selective upgrading of bioderived feedstocks under mild reaction conditions.
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Tuning Cu+ species/Brønsted acids of copper phyllosilicate by K+ doping for selective hydrogenation of methyl palmitate to hexadecanol
(2023-12-01)
Prasanseang, Warot
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Choojun, Kittisak
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Poo-arporn, Yingyot
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Huang, Ai Lin
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Lin, Yu Chuan
Selective hydrogenation of methyl palmitate to hexadecanol can be manipulated by tuning Cu+ species and Brønsted acid sites (BAS) of copper phyllosilicate (CuPS) catalysts with K+ doping. The catalysts were prepared by impregnating K+ onto reduced and non-reduced CuPS. The reactions were carried out in a fixed-bed flow reactor at 250 °C under atmospheric H<inf>2</inf>. In situ TR-XANES and Py-IR suggest that the presence of K+ could stabilize Cu+ species and neutralize BAS. As compared to the non-reduced sample, K+ loading (0.01–0.10 wt%) on the reduced CuPS provide higher Cu+ fraction (10–16%), lower BAS (0.82 to 0.16μ mol/g) and lower Cu dispersion (75 to 52%). A balance between Cu0 active surface and Cu+ content provides an optimum hydrogenation activity (up to 80 %). The increased Cu+ species, together with the decreased BAS, does not only enhance the catalyst stability, but also hexadecanol selectivity (from 35 to 60%, at ∼50% conversion).
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Facile synthesis of the atomically dispersed hydrotalcite oxide supported copper catalysts for the selective hydrogenation of 5–hydroxymethylfurfural into 2,5-bis(hydroxymethyl)furan
(2023-07-15)
Kumar, Raju
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Lee, Hsin Hui
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Chen, En
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Du, Yuan Peng
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Lin, Chan Yi
The selective hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF) using the atomically dispersed supported copper catalyst is investigated. The hydrotalcite oxide supported copper materials (Cu<inf>(x)</inf>HTO) are facilely prepared by coprecipitating metal precursors in a methanolic solution under a tuned pH. The surface characterization involving PXRD, TEM, H<inf>2</inf>/N<inf>2</inf>O-TPR, and XAS reveals unequivocal evidence for the presence of the atomically dispersed copper on HTO surface. XAS specifically indicates the formation of mononuclear copper species, and H<inf>2</inf>/N<inf>2</inf>O-TPR strongly supports the copper atoms of Cu<inf>(5)</inf>HTO are evenly distributed in 99% dispersion. Moreover, the reduced Cu<inf>(5)</inf>HTO (r-Cu<inf>(5)</inf>HTO) enables to completely hydrogenate HMF to BHMF under mild conditions, in comparison to the poor reactivity catalyzed by the hydrotalcite oxide supported copper nanoparticles (r-Cu<inf>(4)</inf>@HTO). The dramatic enhancement of HMF hydrogenation catalyzed by r-Cu<inf>(5)</inf>HTO can be attributed to the fine distribution of copper atoms which are situated homogeneously over HTO surface as well as chemically reactive for the carbonyl group.
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Linear long-chain α-olefins from hydrodeoxygenation of methyl palmitate over copper phyllosilicate catalysts
(2022-04-05)
Prasanseang, Warot
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Choojun, Kittisak
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Poo-arporn, Yingyot
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Huang, Ai Lin
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Lin, Yu Chuan
Copper phyllosilicate (CuPS) was used as a bifunctional catalyst for hydrodeoxygenation of methyl palmitate (MP) to produce long-chain α-olefins without the loss of carbon backbone. The CuPS catalysts were prepared by ammonia evaporation-hydrothermal method. The crystal structure, surface area, reducibility, Cu dispersion, Cu particle size and acidity of the catalysts were examined by XRD, BET, H<inf>2</inf>-TPR, TEM, NH<inf>3</inf>-TPD and Py-IR. The existence of Cu2+ species (octahedral (O<inf>h</inf>)/square planar (Sq)), Cu+ and Cu0 upon calcination/reduction was investigated by in situ TR-XANES. The Cu dispersion was related to the Cu+ fraction in CuPS, while Brønsted acid sites (BAS) depends on Cu0 particles. The MP conversion to 1-hexadecene proceeds via hydrogenation-dehydration promoted by the synergy of Cu0 surface and Brønsted acid sites at the interface. The α-olefin selectivity depends on a balance between Cu+ and Cu loading. The 20CuPS possessing 10% Cu+ fraction, provides a high conversion of 72% with 45% α-olefin selectivity.

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