Energy Catalytic Conversion and Environmental Catalytic Purification

Energy shortages, environmental pollution, and climate change have become critical global issues, presenting significant challenges to the sustainable development of human society [1,2]. In this context, advancing a low-energy-consumption and low-carbon economy, reducing dependence on fossil fuels, and restoring ecological environments have emerged as collective priorities [3]. Within this framework, catalytic conversion technology plays a crucial role in addressing the interconnected challenges of energy and environmental sustainability [4].

Advancements in catalytic technology face significant challenges. From a scientific perspective, current catalytic systems are constrained by three fundamental issues [5,6]. First, achieving an optimal balance among catalytic activity, selectivity, and stability remains a persistent challenge [7]. Second, there is a limited understanding of the fundamental catalytic mechanisms, which perpetuates reliance on empirical trial-and-error methods in catalyst development, thereby reducing research efficiency and extending innovation timelines [8,9,10]. Third, rigid reaction conditions impose critical constraints on catalytic applications. From industrial viewpoints, basic research tends to prioritize theoretical breakthroughs while insufficiently addressing engineering problems, such as large-scale catalyst synthesis and ensuring long-term stability under industrial operating conditions [11]. This Special Issue aims to provide a comprehensive overview of recent advances in catalysis for environmental and energy conversion applications, emphasizing both heterogeneous and homogeneous catalysis. The scope includes key topics of both scientific and industrial significance.

Lian et al. provided a comprehensive review of the applications of Mn-based catalysts, including both bulk and supported MnO_x catalysts as well as bulk and supported Mn-based composite oxide catalysts, in the CO-selective catalytic reduction of NO_x (CO-SCR) technology. Compared to other transition metal-based catalysts, Mn-based catalysts demonstrate superior catalytic efficiency under low-temperature and low-oxygen conditions, underscoring their considerable potential for practical applications [Contribution 1].

Gomha et al. synthesized three 2-cyano-N′-(2-cyano-3-azobutyl-2-enyl)-3-azobutyl-2-enyl hydrazides employing L-proline as an organic catalyst. This synthetic approach is notable for the catalyst’s reusability, mild reaction conditions, environmentally benign process, operational simplicity, high product purity, short reaction time, and elevated yield. Consequently, it holds significant importance in the domain of green drug synthesis [Contribution 2].

Another contribution by the Gomha team involves the use of homophenyl tetramethylimide benzoyl thiourea cross-linked chitosan (PIBTUCS) hydrogel as a green biocatalyst for the efficient synthesis of novel thiazole derivatives. A series of new thiazole derivatives were synthesized through the catalysis of the reaction between 2-(4-((2-aminoformylhydrazyl) methyl) phenoxy)-N-(4-chlorophenyl) acetamide and various hydrazone acyl halides as well as α-halogenated ketones [Contribution 3].

Hu et al. discussed the current challenges confronted by biogas dry reforming technology and outlined the future development trends, providing valuable insights and suggestions for subsequent research and industrial applications [Contribution 4].

Adriana et al. highlighted that iron oxides and hydroxides (Fe-OH) extracted from natural sources have attracted extensive attention in a range of catalytic applications, such as advanced oxidation processes (AOPs), electrochemical applications, catalytic cracking, and biodiesel production [Contribution 5].

Carlos et al. synthesized CeO₂ photocatalytic supports via a precipitation method. Their study demonstrated that sulfation, characterized by bidentate coordination between sulfate groups and semiconductor metal ions within the material, results in an increased specific surface area and a decreased average grain size. The surface modification of CeO₂ was confirmed to be feasible, with sulfate groups acting as electron traps during the photocatalytic process. This function reduces the recombination rate of charge carriers and increases the availability of vacancies, thereby enhancing the degradation of pollutants. This mechanism was supported by the material’s high photocatalytic activity in degrading the herbicide 2,4-dichlorophenoxyacetic acid [Contribution 6].

Baaloudj et al. examined the synthesis and properties of a novel silicate material, Bi₁₂SnO₂₀. Due to its unique characteristics and the distinctive structure associated with the I₂₃ space group, this silicate has attracted considerable research attention in recent years. In their study, tetracycline, bisphenol A, and Rhodamine B were utilized as model pollutants, and performance evaluations were conducted under visible light irradiation. The results indicated that, at a pollutant concentration of 20 mg/L, the degradation efficiency reached nearly 100% within 2 h [Contribution 7].

Li et al. investigated the effects of calcination temperature and hydrogen pretreatment on the structural characteristics and catalytic performance of Pt/CeO₂ catalysts. Hydrogen pretreatment induces the formation of oxygen vacancies on the catalyst surface, which is attributed to the reduction of PtO_x to metallic Pt. This facilitates the generation of reactive oxygen species, thereby improving the catalytic oxidation of NO. Experimental results indicated that calcination temperature significantly influences the redox properties of the catalyst, which in turn affects its efficiency in NO oxidation reactions. This research provides important insights for the design and optimization of Pt/CeO₂ catalysts in environmental applications, particularly in the development of exhaust gas post-treatment technologies [Contribution 8].

Almotiry et al. utilized hydrothermally synthesized UiO-67 Metal–Organic Framework (MOF) to evaluate the efficacy of various adsorption parameters in the removal of antiviral drugs, specifically ritonavir (RTV) and lopinavir (LPV), from aqueous solutions. Diffusion kinetic studies revealed that the adsorption process on the surface of UiO-67 MOF is predominantly catalytic. Thermodynamic analyses, including calculations of Gibbs free energy change (ΔG), enthalpy change (ΔH), and entropy change (ΔS), indicated that the adsorption of RTV and LPV onto UiO-67 from aqueous solutions is spontaneous. These results underscore the potential application of UiO-67 MOF as an effective adsorbent for antiviral drugs [Contribution 9].

Guo et al. addressed the problems of low mineralization rates and limited durability in the ozonated catalytic oxidation (OCO) of volatile organic compounds (VOCs) by enhancing the oxygen mobility and low-temperature reducibility of transition metal oxides. They achieved this by incorporating highly dispersed Ag into Mn₃O₄ via a co-precipitation method utilizing oxalic acid. The resulting Ag/Mn₃O₄ catalyst exhibited superior mineralization rates and stability relative to pure Mn₃O₄ during the catalytic ozonation of benzene at ambient temperature. This study is expected to contribute to the improvement of VOC mineralization efficiency through ozonated catalytic oxidation [Contribution 10].

These research directions are interrelated and mutually reinforcing, collectively forming a framework for catalytic technologies aimed at addressing energy and environmental challenges. It is anticipated that the academic exchanges facilitated by this Special Issue will stimulate novel ideas and significant breakthroughs, thereby advancing innovations in catalytic materials, principles, methodologies, and technologies. Moreover, such progress is expected to accelerate the industrial implementation of catalytic technologies in areas such as clean energy conversion and environmental pollution control. Additionally, this Special Issue is envisioned to act as a catalyst for establishing a virtuous cycle encompassing fundamental research, technological development, and industrial application within the global catalysis community. This cycle will foster the widespread adoption of catalytic technologies across the energy, environmental, and chemical engineering sectors, ultimately contributing scholarly expertise toward the realization of a low-carbon, clean, and sustainable future.