Advances in Catalysis for Sustainable Energy and Environmental Remediation

Catalysis plays a key role in advancing sustainable technologies for energy conversion and environmental remediation [1]. With the global energy demand continuing to rise, increasing dependence on fossil fuels is a serious issue because of their emissions of hazardous gases into the environment [2]. Addressing climate change and pollution challenges requires a transition toward green and renewable energy sources. One of the most promising solutions is the development of efficient, scalable, and environmentally benign catalytic systems. Catalysis, as a foundation of green chemistry, not only enables the generation of clean energy and reduces dependence on fossil fuels but also facilitates the transformation of environmental pollutants into valuable energy products. This Special Issue of Catalysts, titled “Advanced Catalytic Materials for Energy and Environmental Applications”, brings together over a decade of our research efforts, spanning photocatalysis, electrocatalysis, advanced oxidation processes, and environmental remediation. Our approach combines theoretical modelling and synthetic effort to design high-performance catalytic materials. Starting from first-principles simulations using density functional theory (DFT) and Molecular Dynamics (MD), we have been working to engineer the atomic and electronic structures of catalysts to optimize reaction kinetics, enhance selectivity, and ensure long-term stability [3,4]. These insights guide the fabrication of materials with minimized cost and maximized efficiency for energy applications. The central theme of this Special Issue is illustrated in Scheme 1. Its aim is to present original contributions that reflect the diversity, creativity, and scientific rigour of current research in catalysis.

In this Special Issue, we showcase a diverse collection of studies that highlight the evolving role of catalysis in energy and environmental technologies. Contributions span from the design of novel catalytic materials for hydrogen storage and fuel cells to the application of computational modelling for performance optimization. Several papers explore sustainable approaches such as recycling consumed energy materials and integrating single-atom strategies for enhanced catalytic activity. Together, these works reflect the interdisciplinary nature of modern catalysis and its potential to address serious global challenges. We hope this collection will inspire further research and innovation toward a cleaner, low-carbon future. Summaries of the published work in this Special Issue are highlighted below.

In the first paper [10], a cost-effective and sustainable electrocatalyst for oxygen evolution reaction (OER), combining nanocellulose-derived biocarbon with Fe/zeolite/carbon nanotubes, is reported. The composite material exhibits high surface area, improved conductivity, and enhanced catalytic activity, surpassing traditional noble metal catalysts. The work demonstrates a promising route for scalable water-splitting technologies using renewable carbon sources and earth-abundant metals.

In the second paper [11], the authors develop a Ni-P-N-C catalyst supported on nickel foam for the urea oxidation reaction (UOR), enabling simultaneous hydrogen production and wastewater treatment. The catalyst shows high activity, low overpotential, and excellent stability due to its porous structure and synergistic effects among Ni, P, and N dopants. This dual-function system offers a sustainable alternative to conventional hydrogen generation methods.

The third contribution is from Wang et al. [12], who introduces an Fe₃S₄/WO₃ composite catalyst for activating peroxymonosulfate (PMS) in advanced oxidation processes. The synergistic interaction between Fe and W sites enhances electron transfer and regenerates Fe²⁺ active sites, improving pollutant degradation efficiency. The study provides insights into designing stable and regenerable catalysts for wastewater treatment.

Hamdalla et al. [13] reports an activated biochar derived from green algae, which was doped with PEDOT:PSS to create a multifunctional composite for photocatalysis and energy storage. The material revealed improved conductivity, surface area, and charge separation, making it suitable for solar-driven reactions and supercapacitor applications. This green synthesis approach aligns with circular economy principles.

In the fifth contribution, from Ma et al. [14], the authors investigate the hydrodeoxygenation (HDO) of phenol using Ni-P catalysts supported on Hβ and Ce-β zeolites. The modified supports enhance metal dispersion and acidity, leading to improved catalytic performance. The findings contribute to biomass valorisation strategies by enabling the efficient conversion of oxygenated compounds into hydrocarbons.

The sixth work of this Special Issue is a review on heterogeneous acid catalysts for biodiesel production [15]. In this review, Hua et al. explore the role of heterogeneous acid catalysts in biodiesel synthesis, emphasizing the impact of physicochemical properties on activity and reusability. It compares various catalyst types, discusses reaction mechanisms, and highlights challenges in scalability and regeneration. The paper serves as a comprehensive guide for designing robust catalysts for sustainable fuel production.

The seventh contribution is from Mekonnin et al. [16], who comprehensively provide a detailed overview of hydrogen storage technologies, including physical, chemical, and hybrid methods. The paper evaluates materials such as metal hydrides, porous frameworks, and liquid carriers, addressing issues of safety, cost, and scalability, and finally, it outlines future directions for achieving efficient and practical hydrogen storage systems in clean energy applications.

The eighth contribution [17] reports the fabrication of sustainable carbon–carbon composites derived from biomass-based pitch, with a particular emphasis on optimizing structural, electrical, and mechanical properties through catalyst engineering strategies. The study demonstrates that the introduction of appropriate catalysts during carbonization promotes ordered carbon structures and improved interfacial bonding, leading to enhanced electrical conductivity and mechanical integrity. By elucidating the relationship between catalyst selection, microstructural evolution, and macroscopic performance, this work provides valuable guidelines for designing high-performance, biomass-derived carbon composites. These materials are highly significant for applications in energy devices, conductive components, and sustainable catalytic systems, reinforcing the importance of renewable carbon resources in next-generation energy and environmental technologies.

Overall, these contributions highlight key emerging directions in modern catalytic research, with a strong emphasis on the development of catalysts based on earth-abundant, non-toxic, and renewable materials, such as biomass-derived carbons, transition-metal phosphides, and doped metal oxides, which offer sustainable and cost-effective alternatives to noble metal systems. Increasing attention is being devoted to multifunctional catalytic platforms that integrate photocatalytic, electrocatalytic, and energy storage functionalities, enabling more efficient, flexible, and versatile energy conversion and environmental remediation processes. In parallel, advances in computational modelling, particularly density functional theory and atomistic simulations, are providing deeper mechanistic insight into structure–property–activity relationships, facilitating the rational design and optimization of catalytic materials. Importantly, scalability and long-term operational stability are increasingly recognized as essential requirements for real-world deployment. Several contributions in this Special Issue directly address these challenges through robust synthesis strategies, realistic performance benchmarking, and systematic durability assessments. In summary, this Special Issue offers a concise yet comprehensive snapshot of the rapidly evolving landscape of catalytic materials for energy and environmental applications. Covering topics ranging from hydrogen production and storage to pollutant degradation, biomass valorisation, and CO₂ conversion, the collected works showcase innovative material designs and fundamental insights that will help shape the future of sustainable catalysis. As Guest Editors, we sincerely thank all authors for their high-quality contributions, the reviewers for their thoughtful and constructive evaluations, and the Catalysts editorial team for their professional support. We hope this collection stimulates continued research, collaboration, and innovation toward the development of advanced catalytic technologies for a cleaner and more sustainable future.