Alkaline Oxidation Research Articles

Ultrafast Electrical Pulse Synthesis of Highly Active Electrocatalysts for Beyond-Industrial-Level Hydrogen Gas Batteries.

The high reliability and proven ultra-longevity make aqueous hydrogen gas (H2 ) batteries ideal for large-scale energy storage. However, the low alkaline hydrogen evolution and oxidation reaction (HER/HOR) activities of expensive platinum catalysts severely hamper their widespread applications in H2 batteries. Here, cost-effective, highly active electrocatalysts, with a model of ruthenium-nickel alloy nanoparticles in ≈3nm anchored on carbon black (RuNi/C) as an example, are developed by an ultrafast electrical pulse approach for nickel-hydrogen gas (NiH2 ) batteries. Having a competitive low cost of about one fifth of Pt/C benckmark, this ultrafine RuNi/C catalyst displays an ultrahigh HOR mass activity of 2.34 A mg-1 at 50 mV (vs RHE) and an ultralow HER overpotential of 19.5 mV at a current density of 10 mA cm-2 . As a result, the advanced NiH2 battery can efficiently operate under all-climate conditions (from -25 to +50 °C) with excellent durability. Notably, the NiH2 cell stack achieves an energy density up to 183Wh kg-1 and an estimated cost of ≈49 $ kWh-1 under an ultrahigh cathode Ni(OH)2 loading of 280mg cm-2 and a low anode Ru loading of ≈62.5µg cm-2 . The advanced beyond-industrial-level hydrogen gas batteries provide great opportunities for practical grid-scale energy storage applications.

Highly Sensitive Determination of Carbamazepine and Oxcarbazepine and Identification of Their Degradation Products in Material Evidences and Human Cadaveric Liver by Gas Chromatography–Mass Spectrometry

The work is devoted to the search for conditions for the sample preparation and determination of carbamazepine and oxcarbazepine and identification of the products of their metabolism and degradation in human liver (post mortem) and material evidences by gas chromatography–mass spectrometry. A QUECHERS approach was developed to the sample preparation of carbamazepine and oxcarbazepine. Amitriptyline was proposed as an internal standard. Degradation products of carbamazepine and oxcarbazepine were studied in model solutions upon alkaline and acid hydrolysis and oxidation; 14 metabolites and degradation products were identified. The main analytical characteristics of the developed procedure were determined. The limits of detection are 0.1 and 0.2 µg/g for carbamazepine and oxcarbazepine, respectively. The developed procedure complies with the Validation Guidelines of the Russian Center for Forensic Medical Examination.

The Possible Role of Anoxic Alkaline High Subcritical Water in the Formation of Ferric Minerals, Methane and Disordered Graphitic Carbon in a BARB3 Drilled Sample of the 3.4Ga Buck Reef Chert.

The present article reports Raman spectroscopic observations of siderite, hematite, disordered graphitic carbon and possibly greenalite inside the quartz matrix of a banded iron sample from the BARB3 core drilled inside the 3.4Ga Buck Reef Chert of the Barberton Greenstone Belt in South Africa. The article also reports Raman spectroscopic observations of quartz cavities, concluding in the presence of water, methane and sodium hydroxide at high concentration leading to pH ~ 15 inside the inclusion, suggesting an Archean water which was strongly basic. FeIII-greenalite may also be present inside the inclusion. The possible role of anoxic alkaline high subcritical water in the formation of ferric minerals and the CO required for the synthesis of molecules of biological interest has been demonstrated theoretically since 2013 and summarized in the concept of Geobiotropy. The present article experimentally confirms the importance of considering water in its anoxic strongly alkaline high subcritical domain for the formation of quartz, hematite, FeIII-greenalite, methane and disordered graphitic carbon. Methane is proposed to form locally when the carbon dioxide that is dissolved in the Archean anoxic alkaline high subcritical water, interacts with the molecular hydrogen that is emitted during the anoxic alkaline oxidation of ferrous silicates. The carbon matter is proposed to form as deposition from the anoxic methane-rich fluid. A detailed study of carbon matter from diverse origins is presented in a supplementary file. The study shows that the BARB3_23B sample has been submitted to ~ 335°C, a temperature of the high subcritical domain, and that the graphitic structure contains very low amounts of oxygen and no hydroxyl functional groups. The importance of considering the structure of water is applied to the constructions of the Neoproterozoic and Archean banded iron formations. It is proposed that their minerals are produced inside chemical reaction chambers containing ferrous silicates, and ejected from the Earth's oceanic crust or upper mantle, during processes involving subduction events or not.

Superhydrophobic Surface Designing for Efficient Atmospheric Water Harvesting Aided by Intelligent Computer Vision.

Atmospheric water harvesting (AWH) is a possible solution for the current water crisis on the Earth, and the key process of AWH has been widely applied in commercial dehumidifiers. To improve the energy efficiency of the AWH process, applying a superhydrophobic surface to trigger coalescence-induced jumping could be a promising technique that has attracted extensive interest. While most previous studies focused on optimizing the geometric parameters such as nanoscale surface roughness (<1 μm) or microscale structures (10 μm to a few hundred μm range), which might enhance AWH, here, we report a simple and low-cost approach for superhydrophobic surface engineering, through alkaline oxidation of copper. The prepared medium-sized microflower structures (3-5 μm) by our method could fill the gap of the conventional nano- and microstructures, simultaneously act as the preferable nucleation sites and the promoter for the condensed droplet mobility including droplet coalescence and departure, and eventually benefit the entire AWH performances. Moreover, our AWH structure has been optimized with the aid of machine learning computer vision techniques for droplet dynamic analysis on a micrometer scale. Overall, the alkaline surface oxidation and medium-scale microstructures could provide excellent opportunities for superhydrophobic surfaces for future AWH.

Lignin Valorization for Added-Value Chemicals: Kraft Lignin versus Lignin Fractions

Lignin is a raw material that can potentially be converted into valuable compounds through depolymerization reactions in addition to its use as a polymer or material. However, the chemical recalcitrance and the heterogeneous composition and structure of lignin make it challenging to establish processes that add value to this complex aromatic biopolymer. In this work, solvent fractionation was applied to obtain lignin fractions with a narrowed molecular weight and specific structural characteristics, improving its homogeneity and purity. A kraft lignin was submitted to fractionation using different ratios of acetone, ranging from 60 to 15% v/v, in aqueous mixtures. The composition, structure, and molecular weight of each fraction were studied and their potential applications were evaluated. The most water-soluble fraction has more phenolic OH, less aliphatic OH groups, and shows the lowest content of aryl-ether linkages, which is in accordance with its highest degree of condensation. On the other hand, the insoluble fraction from the mixture with 60% of acetone has the lowest molecular weight and the highest content of inorganic material. Radar plots were applied for lignin fractions evaluation and the fraction with the highest potential (IF 30:70) was submitted to alkaline oxidation with O2. The results were compared with the products yielded from kraft lignin. An increase of about 13 and 19% was found for vanillin and syringaldehyde, respectively, when the fraction IF 30:70 was submitted to oxidation. In conclusion, the proposed fractionation process showed to be an effective method to obtain lignin fractions with specific composition and structural characteristics that could improve its potential as a source of high added-value monomeric phenolic compounds.

In situ generated layered NiFe-LDH/MOF heterostructure nanosheet arrays with abundant defects for efficient alkaline and seawater oxidation

In situ generated layered NiFe-LDH/MOF heterostructure nanosheet arrays with abundant defects for efficient alkaline and seawater oxidation

POTENTIAL APPLICATIONS OF LIGNIN AND ITS DERIVATIVES FROM LIGNOCELLULOSIC BIOMASS – A REVIEW

Lignin is the second most abundant component of lignocellulose biomass after cellulose with annual production of 70 million tons. Lignin constitutes between 15 to 40 percent of its dry weight, with varying composition in woody plants such as softwood (18-25%) and hardwood (27-33%), and non-woody plant such as grass (17-24%). The polyphenolic polymer is made up of three monolignols such as coniferyl alcohol, sinapyl alcohol, and p-coumaryl alcohol that later forms an aromatic structure consisting of guaiacyl, syringyl, and p-hydroxyphenyl. The highly branched three-dimensional structure is both complex and recalcitrant, hence making its utilization difficult. However, the polymeric lignin can be extracted by various methods such as physical, chemical and biological. The extracted lignin has high potential to be converted into monomeric aromatic derivatives that could serve as a building block for chemical synthesis, biomaterials, bio-oils, wastewater treatment and food industry. The conversion involves several methods such as alkaline nitrobenzene, pyrolysis, catalytic technology, combustion, gasification, hydrocracking and oxidation.

Oxygen-vacancy-rich MoO2 supported nickel as electrocatalysts to promote alkaline hydrogen evolution and oxidation reactions

Hydrogen energy is the most suitable solution for long-term, large-scale energy storage, and the design of efficient, economical, and stable electrocatalysts for hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) is of great significance for its commercial development. Herein, Ni nanocluster supported on oxygen-vacancy-rich MoO2 (Ni/MoO2−x) is designed which contains a large number of oxygen vacancies and Ni–O–Mo bonds. According to X-ray photoelectron spectroscopy, the formation of oxygen vacancies and Ni–O–Mo bonds facilitates the transfer of electrons from Ni to O. The prepared Ni/MoO2−x@NF shows excellent hydrogen electrocatalytic activity, which is proved by a Tafel slope of only 26 mV dec−1 for HER and an exchange current density of 3.64 mA cm−2 for HOR. Theoretical calculations showed optimized free energy of hydrogen adsorption and hydroxide adsorption on Ni/MoO2−x, which can explain the origin of the high activity of the catalyst. This work provides a feasible strategy for designing non-precious metal hydrogen electrocatalytic materials in energy storage.

NiCo-MOF derived nanostructured NiCo-LDH@Ni(OH)2 heterogeneous composite as electrode material for hybrid supercapacitors

Regulating the composition and microstructure of multiphase nanocomposites can be used to significantly improve the charge storage capacity of the materials. Herein, the thermometal NiCo-MOF was used as precursor, which was placed in the designed alkaline oxidation environment for alkalization treatment, and NiCo-LDH and Ni(OH)2 heterogeneous composite (NiCo-LDH@Ni(OH)2) was prepared. The ratio of Ni/Co in MOF precursor was further regulated to optimize the composition and structure. Finally, NiCo-LDH and Ni(OH)2 with two-dimensional nanosheet structure were obtained when the Ni/Co ratio was 2:1. Benefiting from the nanostructure of electroactive material and the synergistic effect of multicomponent heterogeneous composite, the electrochemical reactivity is effectively improved, which the NiCo-LDH@Ni(OH)2 electrode has a specific capacity of 754.8C g−1 at 1 A g−1. Further, hybrid supercapacitor (HSC) is assembled to explore practical applications device, which the NiCo-LDH@Ni(OH)2//AC HSC device can output energy density of 30.6 Wh kg−1, power density of 799.9 W kg−1, and maintain 89.0 % of the initial performance after 5000 cycles.

Application of Unsupervised Learning for the Evaluation of Burial Behavior of Geomaterials in Peatlands: Case of Lignin Moieties Yielded by Alkaline Oxidative Cleavage

Tropical Peatlands accumulate organic matter (OM) and a significant source of carbon dioxide (CO2) and methane (CH4) under anoxic conditions. However, it is still ambiguous where in the peat profile these OM and gases are produced. The composition of organic macromolecules that are present in peatland ecosystems are mainly lignin and polysaccharides. As greater concentrations of lignin are found to be strongly related to the high CO2 and CH4 concentrations under anoxic conditions in the surface peat, the need to study the degradation of lignin under anoxic and oxic conditions has emerged. In this study, we found that the "Wet Chemical Degradation" approach is the most preferable and qualified to evaluate the lignin degradation in soils accurately. Then, we applied PCA for the molecular fingerprint consisting of 11 major phenolic sub-units produced by alkaline oxidation using cupric oxide (II) along with alkaline hydrolysis of the lignin sample presented in the investigated peat column called "Sagnes". The development of various characteristic indicators for lignin degradation state on the basis of the relative distribution of lignin phenols was measured by chromatography after CuO-NaOH oxidation. In order to achieve this aim, the so-called Principal Component Analysis (PCA) has been applied for the molecular fingerprint composed of the phenolic sub-units, yielded by CuO-NaOH oxidation. This approach aims to seek the efficiency of the already available proxies and potentially create new ones for the investigation of lignin burial along a peatland. Lignin phenol vegetation index (LPVI) is used for comparison. LPVI showed a higher correlation with PC1 rather than PC2. This confirms the potential of the application of LPVI to decipher vegetation change, even in a dynamic system as the peatland. The population is composed of the depth peat samples, and the variables are the proxies and relative contributions of the 11 yielded phenolic sub-units.

Forced Degradation and Stability-Indicating Study for the Binary Mixture of Allopurinol and Thioctic Acid Using Validated HPLC-DAD Method.

Careful review of the scientific databases revealed that no stability-indicating analytical method is available for the binary mixture of allopurinol (ALO) and thioctic acid (THA). A comprehensive stability-indicating HPLC-DAD procedure has been executed for concurrent analysis of ALO and THA. Successful chromatographic separation of the cited drugs was reached using a Durashell C18 column (4.6 × 250 mm, 5 µm particle size). The mobile phase consisted of a mixture of acidified water (pH 4.0) using phosphoric acid and acetonitrile pumped in gradient elution mode. For quantification of ALO and THA, their respective peak areas were recorded at 249 and 210 nm. A systematic validation of analytical performance was investigated in terms of system suitability, linearity, ranges, precision, accuracy, specificity, robustness, detection, and quantification limits. ALO and THA peaks emerged at retention times 4.26 and 8.15 min, respectively. Linear ranges for ALO and THA were 5-100 and 10-400 µg/mL, respectively, with correlation coefficient values exceeding 0.9999. Both drugs were exposed to conditions of neutral, acidic, and alkaline hydrolysis, oxidation, and thermal decomposition. Stability-indicating features have been demonstrated by resolution of the drugs from their forced degradation peaks. For verification of peak identity and purity, the diode-array detector (DAD) was used. In addition, degradation pathways for the cited drugs were postulated. Furthermore, separation of both analytes from about 13 medicinal compounds of different therapeutic classes disclosed optimum specificity of the proposed method. Advantageous application of the validated HPLC method for the concurrent analysis of ALO/THA in their tablet dosage form was accomplished. So far, the described HPLC-DAD method is considered the first detailed stability-indicating analytical study for this pharmaceutical mixture.

A novel approach to synthesizing sodium antimonate and recovering lead and zinc from arsenic-bearing antimony white

In this paper, in order to eradicate the high energy consumption, environmental pollution of As2O3 dust and hazardous arsenic–alkali residue in a traditional arsenic–bearing antimony white (A–BAW) disposal in pyrometallurgical process of jamesonite, a novel aqueous alkaline oxidation was proposed to directly synthesize sodium antimonate and recover valuable Pb and Zn. Based on the thermodynamic analysis and experimental research, sodium antimonate was prepared at [NaOH] = 8 mol/L, η[H2O2] = 1.4, ratio of liquid to A–BAW = 3:1, and reaction temperature = 80 °C. The as–prepared NaSb(OH)6 was a cubic structure having a uniform size of 5–10 um. The mother liquor was purified at 2.0 times of theoretical Na2S dosage and 10 °C as a result of PbS, ZnS and Na3AsO4·12H2O richened in crystal slags with the precipitation ratios of 99.64 % (Pb), 99.75 % (Zn) and 95.81 % (As), respectively. Furthermore, PbS and ZnS were effectively recovered by water–leaching with precipitation ratios for 99.99 % (Pb) and 99.98 % (Zn). This novel approach not only comprehensively recovers valuable metals and eliminates arsenic pollution but also realizes an economically sustainable utilization of antimonial resources from the pyrometallurgical process of jamesonite.

Effect of hydrophilic properties of packings on mass transfer performance of water distillation

Water distillation as an effective method for detritiation and deuterium enrichment can be used to improve mass transfer efficiency by treating the packing surface. This study focuses on the effect of the wettability of the packings surface on the separation performance of the H2O-HDO system. Different hydrophilic effect coatings are prepared on the surface of copper packings by alkaline etching and oxidation method. The differences in mass transfer performance of packings with different contact angles are investigated. It is found that with the increase of hydrophilicity, the mass transfer performance of the packing is relatively improved. By combining empirical models of mass transfer and experimental data, a mathematical model for predicting the height equivalent of theoretical plate (HETP) is established to quantify the effect of wetting properties on the mass transfer process.

Reversible alkaline hydrogen evolution and oxidation reactions using Ni–Mo catalysts supported on carbon

Carbon-supported Ni–Mo composites catalyze alkaline hydrogen evolution and oxidation with negligible onset overpotential. Electrolyzers using Ni–Mo cathodes perform comparably to Pt–Ru cathodes, but oxidative instability limits fuel cell operation.

Stability Indicating Method for a Thiazolylhydrazone Derivative with Antifungal Activity and Experimental/Theoretical Elucidation of Its Degradation Products

RN104 (2-[2-(cyclohexylmethylene)hydrazinyl]-4-phenylthiazole) is a thiazolylhydrazone derivative with promising in vitro and in vivo antifungal activity. A stability indicating high performance liquid chromatography with diode-array detection (HPLC-DAD) method was carried out using C18 end-capped column (250 × 4.6 mm, 5 μm) and a mobile phase composed of water and acetonitrile (15:85 v/v) at a flow rate of 1.2 mL min-1, injection volume 25 μL and DAD detection at 240 nm. The method showed to be selective, linear in the range of 20 to 240 μg mL-1, precise, accurate and robust. RN104 forced degradation study under different stress conditions (acidic, alkaline and neutral hydrolysis, oxidation, photolysis and thermolysis) was performed using the validated analytical method. The results showed that RN104 underwent significant degradation when subjected to alkaline hydrolysis and oxidation by metallic ions. Quantum mechanics calculations were carried out to assist in the structural elucidation of the formed degradation products. The obtained data may be useful for the development of future formulation based on RN104.

Hierarchical Structures Composed of Cu(OH)2 Nanograss within Directional Microporous Cu for Glucose Sensing.

Cu(OH)2 nanomaterials are widely investigated for non-enzymatic glucose sensors due to their low-cost and excellent performance. Cu(OH)2 nanomaterials usually grow on substrates to form sensor electrodes. Reported works mainly focus on structure adjusting of the Cu(OH)2 nanostructures, while the optimization of substrates is still lacking. In the present work, directional porous Cu (DPC) was applied as the substrate for the growth of Cu(OH)2 nanograss (NG), and hierarchical structures of Cu(OH)2@DPC were prepared by alkaline oxidation. The morphology and microstructure evolution of the prepared hierarchical structures was investigated, and the non-enzymatic glucose sensing performance was evaluated. Cu(OH)2@DPC exhibits enhanced comprehensive non-enzymatic glucose sensing performance compared to the reported ones, which may benefit from both the effective adsorption of the Cu(OH)2 NG with a relatively high surface area and the high solute exchange of the DPC by a channel effect. This work provides new insights into the further improvement of the non-enzymatic glucose sensing performance of Cu(OH)2 nanostructures by optimizing the substrate structure.

Cu/CuO/ZnO/PPy heterojunction material was prepared for Hg2+ anti-interference detection in seawater

Hg2+ pollution poses a major threat to human health and the ecological environment, but there is still a lack of direct and sensitive Hg2+ detection technology. In this study, Cu/CuO/ZnO wires were prepared by alkaline oxidation and hydrothermal methods. Polypyrrole (PPy) was covered on the surface of the material by electrochemical polymerization. Using the principle of electrochemical signal response driven by p-n junction barrier, the material was used for the direct electrochemical detection of Hg2+ and was tested by differential pulse voltammetry. The composite has a good linear relationship in the Hg2+ concentration range of 200–1600 nmol/L, and has ultra-high sensitivity (1,010.82 μA∙L/(nmol∙cm2)) and ultra-low detection limit (2.1 pmol/L). The new sensing mode based on the interface barrier eliminates the interference of other ions. The recovery rate of Hg2+ in tap water, river water and sea water is 97.3%–105.0%, and the RSD is 1.8%–5.6%. This method using p-n junction barrier can be extended to the development and research of other sensors for detecting heavy metal ions.

Recovery of V2O5 from spent SCR catalyst by H2SO4-ascorbic acid leaching and chemical precipitation

Large amounts of spent selective catalytic reduction (SCR) catalysts were produced in industry after losing their activity. This study developed a clean and effective route of leaching and recovery of vanadium (V) from spent SCR catalyst. First, ascorbic acid (C6H8O6) as the adjuvant can enhance vanadium leaching in H2SO4 solution. The effect parameters of acid concentration, leaching temperature, leaching time and liquid-solid (L/S) ratio on the leaching efficiency of vanadium were investigated. Then, the enrichment of vanadium in the leachate to obtain the black cake was carried out through adjusting pH value. The effects of vanadium concentration and pH on the precipitation efficiency of vanadium were studied. Finally, after alkaline dissolution and oxidation of the black cake, ammonium chloride (NH4Cl) was selected and used as the precipitant to obtain the ammonium poly-vanadate (APV). The final product vanadium pentoxide (V2O5) was obtained through roasting APV at 550 ℃ for 1.0 h. The black cake, APV and V2O5 were analyzed by the characterization of XRD or XRF. This study may introduce a new perspective for the effective usage of vanadium from spent SCR catalyst.

A meta‐analysis on the impacts of different oxidation methods on the surface area properties of biochar

AbstractBiochar has a beneficial impact on agricultural prosperity, according to numerous studies, and the key dispute presently is how to maximize that impact. Biochar oxidation is well‐known as one of the accepted methods for increasing biochar efficiency. However, due to contradictory data presented in studies and because biochar is derived from diverse oxidation procedures, as well as, the lack of an analytical comparison between different methods, oxidation data sets require a thorough assessment that can be covered by meta‐analysis. In this study, the effects of the five most common oxidation methods in the literature, namely oxidation by acids, alkaline, metal oxides, physical, and natural oxidation, on the cation exchange capacity (CEC), micro‐pores (MP), specific surface area (SSA), and oxygen‐content functional groups (OFGs) of biochar, were meta‐analyzed. When pyrolysis conditions varied, the efficiency of various operations was also addressed. The most efficient method was acidic oxidation, which increased CEC, SSA, MP, and OFGs by 46%, 43%, 55%, and 72%, respectively. Additionally, increasing the pyrolysis temperature above 550°C is critical for lowering OFGs, which has an impact on biochar sorption characteristics. According to the findings, biochar oxidation (post‐pyrolysis) is important since it creates more oxide ions on the surface area than feedstock oxidation (pre‐pyrolysis). Due to their high inorganic nutrient content, crop residues such as rice husk, maize stalk, and rapeseed stem, which were classed in the intermediate group in this study, are promising feedstocks for synthesizing biochars with high SSA, MP, and CEC. Overall, when compared to other approaches, the acidic process significantly improves the surface properties of biochar.

The Catabolic System of Acetovanillone and Acetosyringone in Sphingobium sp. Strain SYK-6 Useful for Upgrading Aromatic Compounds Obtained through Chemical Lignin Depolymerization.

Acetovanillone is a major aromatic monomer produced in oxidative/base-catalyzed lignin depolymerization. However, the production of chemical products from acetovanillone has not been explored due to the lack of information on the microbial acetovanillone catabolic system. Here, the acvABCDEF genes were identified as specifically induced genes during the growth of Sphingobium sp. strain SYK-6 cells with acetovanillone and these genes were essential for SYK-6 growth on acetovanillone and acetosyringone (a syringyl-type acetophenone derivative). AcvAB and AcvF produced in Escherichia coli phosphorylated acetovanillone/acetosyringone and dephosphorylated the phosphorylated acetovanillone/acetosyringone, respectively. AcvCDE produced in Sphingobium japonicum UT26S carboxylated the reaction products generated from acetovanillone/acetosyringone by AcvAB and AcvF into vanilloyl acetic acid/3-(4-hydroxy-3,5-dimethoxyphenyl)-3-oxopropanoic acid. To demonstrate the feasibility of producing cis,cis-muconic acid from acetovanillone, a metabolic modification on a mutant of Pseudomonas sp. strain NGC7 that accumulates cis,cis-muconic acid from catechol was performed. The resulting strain expressing vceA and vceB required for converting vanilloyl acetic acid to vanillic acid and aroY encoding protocatechuic acid decarboxylase in addition to acvABCDEF successfully converted 1.2 mM acetovanillone to approximately equimolar cis,cis-muconic acid. Our results are expected to help improve the yield and purity of value-added chemical production from lignin through biological funneling. IMPORTANCE In the alkaline oxidation of lignin, aromatic aldehydes (vanillin, syringaldehyde, and p-hydroxybenzaldehyde), aromatic acids (vanillic acid, syringic acid, and p-hydroxybenzoic acid), and acetophenone-related compounds (acetovanillone, acetosyringone, and 4'-hydroxyacetophenone) are produced as major aromatic monomers. Also, base-catalyzed depolymerization of guaiacyl lignin resulted in vanillin, vanillic acid, guaiacol, and acetovanillone as primary aromatic monomers. To date, microbial catabolic systems of vanillin, vanillic acid, and guaiacol have been well characterized, and the production of value-added chemicals from them has also been explored. However, due to the lack of information on the microbial acetovanillone and acetosyringone catabolic system, chemical production from acetovanillone and acetosyringone has not been achieved. This study elucidated the acetovanillone/acetosyringone catabolic system and demonstrates the potential of using these genes for the production of value-added chemicals from these compounds.