Sustainable Energy & Fuels最新文献

A novel sustainable synthesis strategy for producing a range of structurally distinct zeolites, specifically Zeolite 4A, Zeolite 13X, and Zeolite Y, is presented. This method avoids organic templates (commonly used for many high-silica zeolites such as ZSM-5, Beta, or high-silica Y) and directly produces Zeolite 4A, Zeolite 13X, and Zeolite Y from natural bentonite clay without the need for synthetic silica or alumina sources and thus offers a much more environmentally-benign production strategy than existing commercial synthetic routes. By systematically tuning alkaline fusion conditions and hydrothermal crystallization parameters, selective zeolite phase formation is achieved: lower fusion temperatures and NaOH/clay ratios favor the formation of LTA-type Zeolite 4A, while higher values promote the formation of FAU-type Zeolite 13X and Zeolite Y. The synthesized zeolites demonstrated structural characteristics and adsorption performance comparable to their commercial counterparts. Zeolite 13X exhibited the highest CO₂ adsorption capacity, attributed to its elevated microporosity and sodium content, while Zeolite Y showed enhanced hydrothermal stability and reduced water affinity, resulting from its higher Si/Al ratio and lower cation density. Water vapor adsorption isotherms and repeated cycling tests revealed clear differences in hydrothermal stability between the synthesized zeolites. A cradle-to-gate life cycle assessment (LCA), performed for Zeolite 13X as a representative product, revealed a ∼90% reduction in global warming potential (2.48 vs. 24.25 kg CO₂ eq. per kg), over 95% lower cumulative energy demand, and significantly decreased ecotoxicity and human toxicity indicators when compared to conventional chemical synthesis. Additionally, cost-oriented economic analysis showed that the clay-based synthesis route reduces the production cost of Zeolite 13X by approximately 33% compared to conventional chemical synthesis. Overall, this work provides a mechanistically informed, environmentally friendly framework for the phase-selective synthesis of industrially relevant zeolites from natural clay.

Developing efficient and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) remains a central challenge for sustainable hydrogen production, as the replacement of platinum with non-precious metals is often limited by insufficient intrinsic activity and poor structural stability. In this context, carbon nanotubes (CNTs) have emerged as more than simple conductive additives and increasingly serve as active platforms for regulating electron transport, stabilizing catalytic species, and tailoring local reaction environments. This review adopts a materials design perspective rather than a conventional element based classification, and systematically examines how different design strategies exploit carbon nanotube frameworks to construct efficient non-precious metal HER catalysts. Representative approaches including single atom site engineering, heterointerface formation, multi metallic synergy, and defect or strain induced electronic modulation are discussed. Recent progress in CNT-based macroarchitectures aimed at improving mass transport and long-term electrode robustness is also summarized. By comparing these strategies across multiple length scales, this work extracts general structure activity and stability relationships, highlights recurring design principles that govern catalytic performance, and outlines future research directions toward more controllable synthesis, operando mechanistic understanding, and scalable electrode implementation.

Vacancy and strain engineering have been identified as effective approaches for modulating the oxygen evolution reaction (OER) activity of electrocatalysts. Applying external fields like magnetic and light fields to electrocatalysts is also a potential approach to enhance the OER activity. However, the influence of the dual magnetic and light fields on the OER performance of electrocatalysts subjected to both vacancy and strain engineering remains unexplored. Herein, we rationally prepared epitaxial single-crystal LaNiO₃ (LNO) thin films as model electrocatalysts on LaAlO₃ (LAO) substrates under different oxygen pressures via pulsed laser deposition (PLD), obtaining LNO thin films with compressive strain and tunable oxygen contents. It is found that a volcano-shaped relationship exists between the OER activity and the oxygen content. This relationship originates from the synergistic modulation of both the Ni²⁺/Ni³⁺ ratio and the d-band center position in the LNO thin films. Furthermore, the LNO thin films exhibit a higher OER activity under dual magnetic and light fields compared to those under no external fields, irrespective of their oxygen content. The enhanced OER activity under dual magnetic and light fields primarily stems from the generation of photogenerated electron–hole pairs and the formation of triplet-state oxygen species, collectively reducing the energy barrier for the OER process.

The escalating urgency to address climate change has intensified global interest in technologies capable of converting carbon dioxide (CO₂) into value-added products. This review provides an in-depth examination of earth-abundant metals including Cu, Fe, Ni, Zn, Co and Mo as sustainable and economical alternatives to precious-metal systems for CO₂ reduction. Unlike earlier reports, this work brings together recent progress in both electrochemical and photocatalytic CO₂ conversion, offering a unified perspective on how different reaction environments influence catalyst performance. Emphasis is placed on emerging catalyst architectures such as single-atom sites, dual-atom and alloy configurations, metal–ligand coordinated systems, and advanced hybrid materials. A central theme of this review is the mechanistic challenge associated with C–C coupling and the generation of multi-carbon (C₂⁺) products, an area where single-atom catalysts frequently encounter intrinsic limitations. By integrating recent insights into coordination tuning, multi-site catalytic design and support-induced electronic modulation, we highlight promising strategies to enhance product selectivity and overall catalytic activity. The article also discusses key barriers that continue to hinder large-scale deployment, including limited stability under industrial current densities, site restructuring and deactivation pathways, and mass-transport constraints within practical reactor architectures. Finally, we outline emerging design principles and future research directions that could facilitate the development of durable, high-performance catalysts for sustainable CO₂ transformation. Overall, this review provides a comprehensive and forward-looking framework for advancing earth-abundant metal catalysts toward efficient CO₂ conversion and the realization of a circular carbon economy.

The photocatalytic conversion of carbon-dioxide (CO₂) to methanol (CH₃OH) under mild conditions has been regarded as a promising, cost-effective, and environmentally sustainable approach for carbon utilization and renewable fuel generation. However, the process has been hindered by limited charge separation efficiency and insufficient CO₂ activation. In this study, a heterostructured Ag–Si/MgO/ZnO photocatalyst was rationally designed and synthesized via a solid-phase reaction method. A CH₃OH production rate of 357.53 µmol g_cat⁻¹ h⁻¹ was achieved over the optimized 10% Ag–Si/MgO/ZnO composite catalyst at 250 °C, representing a substantial enhancement compared to the Si/ZnO and Si/MgO/ZnO photocatalysts. The CH₃OH production performance was found to be higher in the photocatalyst/gas-phase system than that reported in comparable studies. The theoretical activation energy for Ag–Si/MgO/ZnO was found to be 158.14 kJ mol⁻¹, which is lower than that of Si/MgO/ZnO (167.79 kJ mol⁻¹) and Si/ZnO (177.97 kJ mol⁻¹), indicating enhanced CO₂ activation and higher CO₂ conversion. More importantly, after more than 72 h of irradiation, the system still exhibited a high CH₃OH production rate, demonstrating its potential for practical application.

In the past decade, outstanding efforts and significant advancements have been achieved on the development of sodium-ion batteries (SIB) with flexible electrodes. Beyond the focus on the electrochemical performance of SIBs, free-standing flexible electrodes for large reversible capacities with superior rate and cycle performances are attributed to structural features, including hierarchical pore bulk that provides a large surface area in hard carbon (HC) materials. Robust structural stability for repeated bending and twisting stresses requires the nanofiber mesh with an inter-networked structure in a flexible sodium-ion full cell, which worked with a high working voltage. It is, therefore, an extensive research effort on flexibility and durability issues for the free-standing electrodes comprised of a range of materials for flexible SIBs. Interfacially compatible flexible materials pose major challenges, including the high safety demand of electrolytes; however, there is a major focus on next-generation HC materials and flexibility. In this review, first, the significance of HC materials are discussed in the context of reversible specific capacity and their random orientation with a curved and defective non-graphitized turbostratic structure with large inter-distance of sheets. Sodium-ion insertion mechanism, energy density, and flexible free-standing electrode are the three major directions of advancement discussed herein. We critically compared and systematically analyzed cell configurations, flexible battery cells, and sodiation/desodiation mechanisms. Subsequently, beyond cell configurations, this review presents a broad, macro perspective on anode materials, highlighting critical features such as redox at the electrode–electrolyte interface, the origin of flexibility, and cell configuration, with a deep understanding of SIB devices.

Physisorption-based materials such as metal–organic frameworks (MOFs), covalent organic frameworks (COFs), and porous carbons have been extensively studied for hydrogen storage due to their high surface areas and tunable pore structures. While these materials show high hydrogen uptake at cryogenic temperatures, storage at ambient conditions (0–50 °C) remains challenging due to weaker binding energies. To improve ambient-temperature performance, various approaches, including metal doping, pore engineering, and functionalization, have been explored. However, some reported ambient-temperature uptake values approach those seen only at cryogenic conditions, raising concerns about measurement errors and reproducibility. This review highlights these challenges and stresses the need for standardized experimental protocols and transparent data sharing. By minimizing errors and fostering reproducibility, future research can accelerate the development of practical, scalable hydrogen storage technologies operable at near-ambient conditions.

Metal-halide perovskite quantum dots (PQDs) exhibit outstanding optoelectronic properties but suffer from poor chemical stability and rapid charge recombination, severely restricting their photocatalytic applications. Encapsulating PQDs within porous metal–organic frameworks (MOFs) via ship-in-a-bottle, bottle-around-ship, or one-pot synthetic routes effectively overcomes these limitations through spatial confinement, surface passivation, and strong interfacial coupling. The resulting PQD@MOF heterostructures demonstrate remarkable moisture, thermal, and photostability, with charge-separation lifetimes extended to hundreds of nanoseconds or even microseconds. Favorable type-II or Z-scheme band alignments and strong quantum confinement provide thermodynamic driving forces of 0.7–1.4 eV, enabling sacrificial-agent-free and noble-metal-free photocatalysis. Benchmark systems achieve record electron consumption rates exceeding 660 µmol g⁻¹ h⁻¹ with ∼100% formate selectivity in CO₂ photoreduction, H₂ evolution rates up to 154 µmol h⁻¹ without cocatalysts, and >99% selectivity in aerobic C–H oxidation reactions. This review elucidates synthesis–structure–activity relationships, clarifies confinement-induced charge-transfer mechanisms, critically compares nine representative systems, and outlines a roadmap toward scalable, lead-free PQD@MOF photocatalysts for practical solar fuel production and fine-chemical synthesis.

The transition from pilot-scale to grid-scale hydrogen production via water electrolysis requires electrocatalysts that simultaneously exhibit high activity, durability, and scalability. Here, we report a hierarchically engineered two-dimensional (2D–2D) hybrid catalyst comprising NiMo-layered double hydroxide (NiMo-LDH) nanoflowers hydrothermally grown on highly exfoliated MXene nanosheets supported by a porous nickel foam. Scanning electron microscopy reveals an interwoven architecture in which NiMo-LDH nanoflowers are intricately anchored within delaminated MXene layers, effectively suppressing nanosheet restacking and maximizing active site exposure while facilitating rapid gas diffusion. The negatively charged surface terminations of MXene further enhance intrinsic activity by modulating interfacial electronic coupling and optimizing water molecule adsorption on NiMo-LDH. Benefiting from this synergistic design, the NiMo-LDH/MXene hybrid electrocatalyst achieves low overpotentials of 266 mV and 290 mV versus the reversible hydrogen electrode (RHE) at 50 mA cm⁻² for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. At higher operational scales, the electrode delivers 200 mA cm⁻² at an overpotential of 373 mV for the HER and 320 mV for the OER, underscoring its capability for delivering industrially relevant current densities. The catalyst also exhibits robust long-term durability, sustaining stable operation for nearly 90 h and maintaining highly stable and low potentials of 3.24 V and 4.28 V at industrially relevant current densities of 300 and 1000 mA cm⁻², respectively. High faradaic efficiencies of ∼94% for the HER and ∼80% for the OER are simultaneously attained under alkaline conditions. This work highlights the rational integration of layered double hydroxides with conductive 2D materials as an effective route to enhance charge transfer, structural stability, and electrocatalytic efficiency, thereby offering a promising platform for next-generation water-splitting systems aimed at large-scale renewable hydrogen production.