Promote Hydrogen Production Research Articles

Evaluation of the synergistic effect of platinum-supported graphene materials on methylcyclohexane decomposition via flow reactor experiments and reactive force-field molecular dynamics simulations

Hydrogen technology is a viable alternative to carbon-based energy sources. However, the widespread use of hydrogen energy is limited by its low volumetric energy density, complex supply chain, and difficulties related to hydrogen storage. This study investigates the influence of Pt-supported graphene additives on hydrogen formation and decomposition of methylcyclohexane (MCH), which is a potential hydrogen carrier, by conducting high-pressure liquid flow reactor experiments and reactive force-field molecular dynamics simulations. This investigation represents a notable improvement in the MCH decomposition and hydrogen generation efficiencies through enhanced catalytic dehydrogenation facilitated by Pt-decorated functionalized graphene sheets (Pt@FGSs). Experimental results indicate that under fixed reaction conditions, the bicomposite structure of the Pt@FGSs at a loading concentration of 50 ppmw reduces the dehydrogenation energy and increases the conversion rate by up to 45%. The yields of products such as hydrogen and low-carbon species are also significantly improved. Notably, hydrogen formation is enhanced by a factor of approximately 2, demonstrating the effectiveness of Pt@FGSs in facilitating fuel decomposition and promoting hydrogen production. In addition, reactive force-field molecular dynamics simulations elucidate possible enhancement mechanisms, in which Pt nanoparticles attach to FGSs and catalyze the dehydrogenation of MCH and its derivatives. The production of a higher amount of the produced hydrogen is evidenced by the desorption of H atoms attached to the Pt surface. This study provides valuable insights that can accelerate the transition towards sustainable and effective decarbonization strategies using MCH as a hydrogen carrier.

Modulating d-p-band electron coupling by N-doping for promoting CuSAs-N/TiO2 photocatalytic hydrogen evolution

Doping can effectively improve the light absorption of single-atoms photocatalysts, but the metal-support interaction (MSI) and surface electronic structure will change due to doping, which needs further study. Herein, we report a nano-TiO2 co-modified with internal doping of N and surface loading of Cu single atoms (CuSAs-N/TiO2) for photocatalytic water-splitting hydrogen evolution. Experimental and theoretical studies confirm that the internal doped N can interact strongly with the surface-loaded CuSAs by modulating the d-p-band electronic coupling. The enhancement of d-p-band electronic coupling enhances the strong electron interaction between CuSA and support of N-doped TiO2. Especially, it significantly affects the d-p-band electronic structure of the catalyst surface lattice and causes electron redistribution in the local structure of surface CuSAs, which can optimize the surface hydrogen evolution kinetics and promote hydrogen production. Consequently, the photocatalytic hydrogen evolution activity, photoelectric response rate and light energy utilization of CuSAs-N/TiO2 are significantly improved. This work reveals the fundamental necessity of d-p-band electron coupling in MSI and catalyst surface electronic structure for driving solar water splitting. It provides valuable insights for the rational design of metal single-atom photocatalysts with high activity and efficient light energy utilization.

Perovskite/cobalt-based metal-organic framework hybrid promotes hydrogen production from oilfield wastewater electrolysis

Hydrogen has been recognized as a new green energy source. However, in regions where fresh water is scarce, research on the use of complex water systems, such as seawater and oilfield wastewater, to produce hydrogen by electrolysis instead of fresh water has become a pressing issue. In this paper, a low-cost and easy-to-synthesized hybrid catalyst composed of perovskite oxide SrCo0.7Fe0.3O3-δ (SCF) and cobalt-based metal-organic framework (Co-MOF) were synthesized using a simple and feasible in-situ coprecipitation method and exhibited excellent hydrogen evolution reaction (HER) activity in oilfield wastewater. The improvement of activity can be attributed to the synergistic effect between the two materials, which have more concentration of oxygen vacancies and more HER active sites due to Co ion migration. This work provides a practical approach to enhance HER activity in complex water systems by constructing spatial composite structures.

Enhance Hydrogen Production from Water Using 532 Lasers

ABSTRACT: hydrogen production via water electrolysis under the influence of laser sounds fascinating with its unique properties, was particularly effective in promoting hydrogen production. The mechanism by which the laser promotes hydrogen production The electrolytic cell used in this work contains 270 ml of distilled water stimulated with different amounts of alcohol (2 ml - 4 ml - 6 ml - 8 ml - 10 ml). This chamber consists of two vertically oriented cylinders. Inside each cylinder there are graphite electrodes, each measuring 10 x 5 x 7 mm3, connected to the positive and negative terminals of a direct current power source, in addition to using a green laser source (532). An efficiency study was conducted using a green laser with a wavelength of 532 nanometers as an optical light source for water analysis through electrolysis. Results were obtained using both the standard electrolysis method and with the green laser source (532 nm). In the case of standard electrolysis, we obtained (When adding 5 ml of cohol, we get 6.63 hydrogen ), while (Adding 10 ml of ill we get 7.44 of hydrogen ) was obtained when using the laser source. The results indicate that using the laser source enhances hydrogen production significantly compared to standard electrolysis, demonstrating the laser's high effectiveness in electrolysis due to its non-absorptive property in water. This could have significant implications for renewable energy and hydrogen fuel production.

Oxygen vacancy modulation for enhanced hydrogen production via chemical looping water-gas shift

Chemical looping water gas shift (CL-WGS)is prospective to generate high-purity hydrogen with integrated CO2 capture. However, this technology is impeded by the lack of active oxygen carriers at mid-temperatures. Here, we synthesized several Ni-doped CoFe2O4-δ to modulate oxygen vacancies and investigate its effect on promoting hydrogen production reaction via chemical looping water gas shift at 650 °C. The findings delineate that doping Ni considerably lowers the energy barriers associated with the oxygen vacancies formation, thereby augmenting their concentration. The underlying mechanism elucidates that within the CL-WGS process, the transfer of lattice oxygen acts as the rate-limiting step. NixCo1-xFe2O4 lowers the formation energy of oxygen vacancies and facilitates the bulk lattice oxygen diffusion through the bulk. Hence, Ni0.5Co0.5Fe2O4 demonstrates the most reduction depth and reversibility via redox reactions, resulting in an elevated hydrogen yield (∼15.5 mmol g−1) at 650 °C, which surpasses the yield from undoped CoFe2O4 by 1.4 times. This performance remains consistently high with only a minimal decline over 100 cycles. The findings introduce a promising approach to promote the reactivity of oxygen carriers, particularly for mid-temperature applications.

Construction of a Bi2S3/Bi0.5Na0.5TiO3 Composite Catalyst with S Vacancies for Efficient Piezo-Photocatalytic Hydrogen Production.

Photocatalytic hydrogen production with low environmental and economic costs is expected to be a powerful means to alleviate energy and environmental problems. However, how to inhibit the rapid recombination of photogenerated carriers is a challenge that photocatalytic hydrogen production has to face. In this study, the coupling of the piezoelectric effect and vacancy engineering into the photocatalytic reaction process synergistically promoted carrier separation, thereby promoting the improvement of hydrogen production performance. Specifically, the novel dual piezoelectric Bi2S3/Bi0.5Na0.5TiO3 (BS-12/BNT) piezo-photocatalyst rich in S vacancies was synthesized by an impregnation method. The hydrogen generation rate of 5% BS-12/BNT under the combined impact of light and ultrasound was up to 1019.39 μmol/g/h, which is 9.5 times higher than that of pure BNT. Various characterization analyses have confirmed that the piezoelectric-photocatalytic activity of BS/BNT composite materials is significantly improved, mainly due to the introduction of S vacancies and piezoelectric fields, which enhance the absorption of sunlight, reduce interface resistance, and so raise the photogenerated carriers' separation efficiency. In addition, the stability of BS/BNT is significantly better than that of the previously synthesized catalysts. Finally, according to the results of XPS, UV-vis, and ESR, the active groups and possible electron transfer paths generated during the piezoelectric-photocatalytic hydrogen production process were studied. This work presents a new approach to promote hydrogen production performance through the synergistic effect of the piezoelectric effect and S vacancies.

Enhancing the activity of Ni-B catalyst via Cu doping towards hydrogen evolution from NaBH4 hydrolysis

Developing efficient, economical, and eco-friendly catalysts for hydrogen release from hydrogen storage materials such as sodium borohydride (NaBH4) is recognized as an ideal solution to meet the growing demand for clean energy. In the present study the Ni-Cux-B alloy catalysts with different Cu doping content on the corncob (CC) substrate via a facile electroless plating method for the hydrolysis of NaBH4 were synthesized. The structural and morphological characteristics of the synthesized catalysts were investigated using various analytical techniques. The results showed that an appropriate Cu content has a remarkable excitation effect on the catalytic activity of Ni-B. The Cu doping strategy effectively changes the dispersion of metal species and provides more catalytic active sites on the surface of the catalyst. Moreover, the synergistic effect between metals after Cu doping enhances electron transfer and facilitates the adsorption and activation of BH4 and H2O molecules, thereby promoting hydrogen production activity. The optimized Ni-Cu7.2-B catalyst achieved a hydrogen generation rate (HGR) of 1321.56 mL min−1 g−1 in alkaline NaBH4 solution at 303 K, with an activation energy (Ea) of 46.26 kJ mol⁻1. The Ni-Cu7.2-B catalyst exhibits satisfactory stability, retaining 90.8 % of its initial catalytic activity after five cycles.

Assembly of low-voltage driven co-production of hydrogen and sulfur via Ru nanoclusters on metal-sulfur coordination: Insights from DFT calculations

Herein, we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur product. This composite comprises Ru nanoclusters supported on the CuS nanostructure, achieved through simple pulsed laser irradiation in liquid approach. The optimized CuS/Ru-30 electrocatalyst demonstrates remarkable bifunctional electrocatalytic activity, exhibiting a negligible working potential of 0.28 V (vs. RHE) for the anodic sulfion oxidation reaction (SOR) and a minimal overpotential of 182 mV for cathodic hydrogen evolution reaction (HER) to achieve 10 mA cm−2 of current density. Moreover, the CuS/Ru-30 electrocatalyst shows exceptional selectivity for converting sulfion into valuable sulfur during anodic oxidation reactions. Remarkably, in a two-electrode electrolyzer system utilizing CuS/Ru-30 as both the anode and cathode, the SOR + HER coupled water electrolysis system demands only 0.52 V to reach 10 mA cm−2, which is considerably lesser compared to the OER + HER coupled water electrolysis (1.85 V). The experimental results and density function theory (DFT) calculations reveal that the strong electron interaction between CuS and Ru nanoclusters generates a built-in electric field, greatly enhancing electron transfer efficiency. This significantly boosts the HER performance and facilitates the adsorption and production of sulfur intermediates. This study presents a rapid and simple strategy for synthesizing a dual-functional catalyst suitable for low-voltage hydrogen generation while facilitating the recovery of valuable sulfur sources.

Customizing hetero-structured high-entropy alloy/oxide active site by regulating the exsolution strategy for highly efficient water splitting

Transition metals and their oxide materials are crucial in promoting hydrogen production efficiency via water splitting. However, the sluggish reaction kinetics of the oxygen evolution reaction (OER) process at the anode requires synergy between multiple active sites for effective activation and high electrocatalytic performance. In this study, an atomic contacted hetero-structured catalyst between high-entropy alloy (HEA) and high-entropy oxide (HEO) was synthesized for realizing highly active and robust OER. The heterogenous HEA/HEO catalyst was prepared by thermal reduction of the rock-salt HEO oxide of (NiCoFeCuAl)O, grown in situ on Ni foam via a fast self-propagating combustion method. The exsolution of face-centered cubic (FCC) structured NiCoFeCu HEA from the NiCoFeCuAlO matrix is beneficial for establishing a strong electron-transferring effect and providing more active reaction sites. Using combined actions of HEA/HEO heterointerfaces and nanoporous structure, the optimized catalyst (R-SNCFCA4.5) displays excellent OER performance with overpotential of 228 mV at current density of 10 mA cm−2, respectively, exhibiting a Tafel slope of 80.52 mV dec−1, and a 2.8 % decay activity for 100 h in alkaline medium. The R-SNCFCA6 catalyst with high extent exsolution of NiCoFeCu showcases the optimal HER performance. We reported the successful construction of HEA/HEO heterogeneous catalysts and demonstrated their application towards a highly efficient water splitting process.

Effect of lignite addition on hydrogen yield from corn straw

ABSTRACT The hydrogen production by fermentation of simple corn straw is low yield, it is necessary to explore the addition of other substances to increase the hydrogen production of corn straw. Therefore, lignite was used as an additive in this study. The effects of different lignite additions on hydrogen production from corn straw and the changes of substances in the fermentation broth were studied. The results showed that the total gas production of the experimental group with 20% lignite addition was 1.63 mL/g, which was 2.07 times that of the control group without corn straw addition, and the daily hydrogen production peak of the experimental group with 20% lignite addition reached 1.19 mL/g, which was 120.37% higher than that of the control group. The addition of lignite also promoted the degradation of humic acid, benzoic acid, glucose, pyruvic acid, volatile matter and fixed carbon in the reaction system. In summary, lignite has a significant role in promoting hydrogen production from corn straw, and the experimental group with 20% lignite has the best hydrogen production from corn straw. The addition of lignite increased the carbon content in the fermentation system, improved the distribution of organic acids, promoted the consumption of organic matter and fixed carbon, and promoted hydrogen production from corn straw.

Enhanced photocatalytic dehydrogenation of formic acid over ultrafine electron-deficient Pd nanoparticles immobilized on amine-functionalized mesoporous titanium dioxide

Formic acid (FA) has been increasingly favored by researchers as an ideal material for the chemical storage of hydrogen. However, the exploration of photocatalytic hydrogen evolution from FA is less extensive compared to conventional thermal catalytic FA decomposition. Therefore, constructing highly active photocatalysts for H2 release from FA presents a challenging issue. Herein, we employed a strategy that involves Pd nanoparticles (NPs) immobilized on amine-functionalized mesoporous titanium dioxide (TiO2–NH2) to promote hydrogen production from FA under full-spectrum light illumination. Impressively, the as-made 2 wt% Pd/TiO2–NH2 catalyst showed remarkable activity under full-spectrum light (Turnover frequency (TOF) of 1380.5 h−1 at 308 K, H2 selectivity: 100%). Characterization results indicated that the unique mesoporous structure of TiO2–NH2, the synergistic interaction of Pd NPs with –NH2, and the Mott-Schottky heterojunction are primarily responsible for the excellent photocatalytic performance of 2 wt% Pd/TiO2–NH2. This study modulates the metal-support interactions through surface engineering and proposes a novel and effective method for the construction of high-performance photocatalysts for H2 production from FA or other photoinduced reactions.

Optimizing Hydrogen-Rich Biofuel Production: Syngas Generation from Wood Chips and Corn Cobs

This study investigates gasification using wood chips (WC) and corn cobs (CC) for hydrogen-rich syngas production. A simulation model developed in Aspen Plus was used to evaluate the performance of biomass gasification. The model incorporates a system of Fortran subroutines that automate the definition of input parameters based on the analysis of biomass composition. Furthermore, the model’s equilibrium constants were adjusted based on experimentally measured gas concentrations, increasing the precision of the variations. The numerical results predicted hydrogen yields of 65–120 g/kg biomass, with 60–70% energy efficiency for steam gasification (versus 40–50% for air gasification). The hydrogen concentration ranged from 34% to 40%, with CO (27–11%), CO2 (9–20%), and CH4 (<4%). The gasification temperature increased hydrogen production by up to 40% but also increased CO2 emissions by up to 20%. Higher biomass moisture content promoted hydrogen production by up to 15% but reduced energy efficiency by up to 10% if excessive. Steam gasification with wood chips and corn cobs shows promising potential for hydrogen-rich syngas production, offering benefits such as reduced emissions (up to 30% less CO) and sustainability by utilizing agricultural residues.

Machine learning-based deoxidizer screening for intensified hydrogen production from steam splitting

The design of advanced deoxidizer is the key to promote hydrogen production from chemical looping steam splitting, however, the deoxidizer shows complicated possibility of composition, which results in long duration in material exploitation. In this study, Gibbs free energy change (ΔG) is used as the output of the model, and three machine learning models, Decision Tree, Random Forest, and Gradient Boosting Tree algorithms, are established and optimized for functionalized deoxidizer screening. Results indicate that the Gradient Boosting Tree algorithm shows the best performance, and the RMSE and R2 of the test dataset reach 22.24 and 0.93. Through the analysis of feature importance and Partial Dependence Plots, the effects of different deoxidizer properties on the difficulty of steam splitting can be intuitively displayed. Specifically, 907 groups of feasible deoxidizers were selected from 772,083 ones through the combination of machine learning and high-throughput screening. Steam splitting experiments demonstrate the prediction accuracy of 81.3% by Gradient Boosting Tree model. Several less reported composite deoxidizers such as Y2O3+Fe, SrO + Fe, SrO + Co, Li2O + Fe, Li2O + Co were predicted and experimentally verified. This study provides prominent strategy and new implications for deoxidizer screening, which will substantially promote the sustainable development of steam splitting hydrogen generation.

Electronic modification of Ni active sites by W for selective benzylamine oxidation and concurrent hydrogen production

We present self-supporting W-doped Ni2P nanosheet arrays, serving as bifunctional catalysts for selective electrooxidation of benzylamine (BA) to high-value benzonitrile (BN), while simultaneously promoting hydrogen production. The assembled W-Ni2P/NF||W-Ni2P/NF (NF: nickel foam) electrolyzer requires a voltage of only 1.41 V to achieve a current density of 10 mA cm−2 in alkaline solution containing 25 mmol L−1 BA, exhibiting an impressive Faradaic efficiency 95% for benzonitrile synthesis. In-situ Raman and FTIR spectroscopies identify catalytically active NiOOH centers and key catalytic intermediates. X-ray absorption spectroscopy (XAS) and theoretical calculations suggest that W acts as electron attractors on adjacent Ni atoms, forming an electron-deficient Ni domain that promotes the adsorption and activation of –NH2 group, leading to efficient dehydrogenation into C≡N bonds. The doped W also optimizes the adsorption of hydrogen (ΔGH*) on Ni2P, thus promote the hydrogen evolution. This work highlights the electronic modification of Ni active sites as a key factor for bifunctional electrocatalysis in selective nitrile electrosynthesis and concurrent hydrogen evolution.

Effect of zero-valent iron (ZVI) and biogas slurry reflux on methane production by anaerobic digestion of waste activated sludge.

This study aimed to improve anaerobic digestion (AD) efficiency through the addition of zero-valent iron (ZVI) and biogas slurry. This paper demonstrated that methane production was most effectively promoted at a biogas slurry reflux ratio of 60%. The introduction of ZVI into anaerobic systems does not enhance its bioavailability. However, both biogas slurry reflux and the combination of ZVI with biogas slurry reflux increase the relative abundance of microorganisms involved in the direct interspecific electron transfer (DIET) process. Among them, the dominant microorganisms Methanosaeta, Methanobacterium, Methanobrevibacter, and Methanolinea accounted for over 60% of the total methanogenic archaea. The Tax4Fun function prediction results indicate that biogas slurry reflux and the combination of ZVI with biogas slurry reflux can increase the content of key enzymes in the acetotrophic and hydrotrophic methanogenesis pathways, thereby strengthening these pathways. The corrosion of ZVI promotes hydrogen production, and the biogas slurry reflux provided additional alkaline and anaerobic microorganisms for the anaerobic system. Their synergistic effect promoted the growth of hydrotrophic methanogens and improved the activities of various enzymes in the hydrolysis and acidification phases, enhanced the system's buffer capacity, and prevented secondary environmental pollution. PRACTITIONER POINTS: Optimal methane production was achieved at a biogas slurry reflux ratio of 60%. Biogas slurry reflux in anaerobic digestion substantially reduced discharge. ZVI addition in combination with biogas slurry reflux facilitates the DIET process.

Hydrogen production promotion and energy saving in anaerobic co-fermentation of heat-treated sludge and food waste.

The objective of this paper is to gain insights into the synergistic advantage of anaerobic co-fermentation of heat-treated sludge (HS) with food waste (FW) and heat-treated food waste (HFW) for hydrogen production. The results showed that, compared with raw sludge (RS) mixed with FW (RS-FW), the co-substrate of HS mixed with either FW (HS-FW) or HFW (HS-HFW) effectively promoted hydrogen production, with HS-HFW promoted more than HS-FW. The maximum specific hydrogen production (MSHP) and the maximum hydrogen concentration (MHC) of HS-HFW were 40.53mL H2/g dry weight and 57.22%, respectively, and 1.21- and 1.45-fold as high as those from HS-FW. The corresponding fermentation was ethanol type for HS-HFW and butyric acid type for HS-FW. The net energy production from RS-FW and HS-FW was both negative, but it was positive (2.57MJ) from 40% HFW addition to HS-HFW. Anaerobic fermentation was more viable for HS-HFW.

Evolution of Grain Boundaries Promoted Hydrogen Production for Industrial-Grade Current Density.

The development of efficient and durable high-current-density hydrogen production electrocatalysts is crucial for the large-scale production of green hydrogen and the early realization of hydrogen economic blueprint. Herein, the evolution of grain boundaries through Cu-mediated NiMo bimetallic oxides (MCu-BNiMo), which leading to the high efficiency of electrocatalyst for hydrogen evolution process (HER) in industrial-grade current density, is successfully driven. The optimal MCu0.10-BNiMo demonstrates ultrahigh current density (>2 A cm-2) at a smaller overpotential in 1m KOH (572mV), than that of BNiMo, which does not have lattice strain. Experimental and theoretical calculations reveal that MCu0.10-BNiMo with optimal lattice strain generated more electrophilic Mo sites with partial oxidation owing to accelerated charge transfer from Cu to Mo, which lowers the energy barriers for H* adsorption. These synergistic effects lead to the enhanced HER performance of MCu0.10-BNiMo. More importantly, industrial application of MCu0.10-BNiMo operated in alkaline electrolytic cell is also determined, with its current density reached 0.5 A cm-2 at 2.12V and 0.1 A cm-2 at 1.79V, which is nearly five-fold that of the state-of-the-art HER electrocatalyst Pt/C. The strategy provides valuable insights for achieving industrial-scale hydrogen production through a highly efficient HER electrocatalyst.

Electron syntrophy between mixed hydrogenogens and Geobacter metallireducens boosted dark hydrogen fermentation: Clarifying roles of electroactive extracellular polymeric substances

To modulate the electron transfer behavior of hydrogen-producing bacteria (HPB) for enhanced hydrogen production, Geobacter metallireducens culture (GM) was introduced as an electron syntrophy partner and redox balance regulator in dark fermentation systems with hydrogen-producing sludge (HPS) as inoculum. The highest hydrogen yield was 306.5 mL/g-COD at the GM/HPS volatile solids ratio of 0.08, which was 65.2 % higher than the HPS group. The multi-layered extracellular polymeric substances (EPS) of GM played a significant role in promoting hydrogen production, with c-type cytochromes probably serving as electroactive functional components. The addition of GM significantly improved the NADH/NAD+ ratio, electron transport system activity, hydrogenase activity, and electrochemical properties of HPS. Furthermore, the microbial community structure and metabolic functions were optimized due to the potential syntrophic interaction between Clostridium sensu stricto (dominant HPB) and Geobacter, thus promoting hydrogen production. This study provided novel insights into the interactions among exoelectrogens, electroactive EPS, and mixed HPB.

Hydrogen production from complete dehydrogenation of hydrazine borane on carbon-doped TiO2-supported NiCr catalysts

C-doped mesoporous TiO2-supported Cr(OH)3 modified Ni nanoparticles (Ni–Cr/CTO) with different morphologies were synthesized by a simple wet-chemical method and used as efficient catalysts for hydrogen production from hydrazine borane.

Study on the mechanism of constructing structure defects on surface of activated carbon with carbon black to promote hydrogen production by thermal-decomposition of methane

Hydrogen production from catalytic decomposition of methane is a promising method of hydrogen production that caters to low-carbon energy sources. The low cost and easy regeneration of carbon-based catalysts is more compatible with the concept of sustainability than metal catalysts. The key problem with catalytic decomposition using activated carbon is the rapid deactivation of the activated carbon due to structural changes caused by the production and accumulation of deposited carbon. Carbon black, on the other hand, exhibits slowly increasing catalytic performance in the catalytic decomposition of methane. Therefore, combining the properties of the two, it is proposed to disperse and load the nano conductive carbon black onto the surface of urea-modified activated carbon, so that the activated carbon can also have self-repairing ability at a later stage. It is shown that the combined application of carbon black loading and urea modification enhances the structural properties of the activated carbon by enriching the microporous structure of the activated carbon surface, increasing the disorder of its crystal structure, and altering the content and concentration of oxygen-containing functional groups on the surface. These microstructural changes combined to enhance the overall catalytic activity of the activated carbon, including its late deactivation time and catalytic performance after deactivation.