Journal of Analytical and Applied Pyrolysis最新文献

{"title":"A strategic approach to treat polyester waste: Co-pyrolysis of PET and PBAT for controlling product characteristics and char graphitization","authors":"Seonho Lee ,&nbsp;Hansung Lee ,&nbsp;Eunhyo Song ,&nbsp;Byungmin Ahn ,&nbsp;Jechan Lee","doi":"10.1016/j.jaap.2025.107527","DOIUrl":"10.1016/j.jaap.2025.107527","url":null,"abstract":"<div><div>This study is aimed at demonstrating pyrolytic behavior of co-pyrolysis of polyethylene terephthalate (PET) and polybutylene adipate terephthalate (PBAT) to propose a method to simultaneously treat a mixed non-biodegradable/biodegradable polyester stream. The co-pyrolysis of PET and PBAT is performed at 500–800 °C. The yields of char and liquid pyrolysate (25 and 22.4 wt%, respectively) are highest at 500 °C, while the yield of gas pyrolysate was highest at 800 °C (18 wt%). Char is the major solid product with yields up to 33 % higher under the co-pyrolysis than under single pyrolysis of PBAT at 800 °C. Structural transformations of the PET/PBAT mixture-derived char depend on pyrolysis temperature. Progressive graphitization with increasing temperature is observed by reduced I_D/G ratios and the appearance of 2D bands. Oxygenated groups (C–O, C<img>O) and formation of C–C or C<img>C bonds are removed with the conversion of PBAT-derived organics, especially at ≥ 700 °C. Micro–mesoporous structures are developed more prominently at higher temperatures. The experimental results should contribute to developing processes achieving the volume reduction of complicated non-biodegradable/biodegradable plastic mixtures and the production of higher quality carbon materials from plastic waste.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107527"},"PeriodicalIF":6.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degradative catalyst solvent extraction and oxidative cracking in humic acid synthesis from municipal sludge","authors":"De-lin Fu,&nbsp;Feng Duan,&nbsp;Li-hui Zhang","doi":"10.1016/j.jaap.2025.107504","DOIUrl":"10.1016/j.jaap.2025.107504","url":null,"abstract":"<div><div>The sustainable conversion of municipal sludge (MS) into humic acid (HA) represents a pivotal strategy for advancing solid waste valorization. However, its high ash and low fixed carbon contents restrict the recovery efficiency of HA.This study introduces an innovative integrated approach combining degradative catalytic solvent extraction and oxidative cracking to achieve efficient HA synthesis.The effects of the temperature, time, pressure and liquid-solid ratio on the HA yield using catalytic extraction product were investigated. Through GC-MS analysis, combined with FTIR and XPS analysis, the reaction mechanism of synthesis was revealed. The results showed that the maximal yield of HA using raw sludge is only 1.85 %. The HA yield of the catalytic extraction products increased by about 22 %, which was 13 times of raw sludge, confirming the superior performance of the proposed method. Acidic sites on HZSM-5 facilitated olefin formation and subsequent aromatization into monoaromatic hydrocarbons (MAHs), benzene derivatives, and polycyclic aromatic hydrocarbons (PAHs), driving a significant rise in fixed carbon content (3.46–48.19 %). Key process limitations were identified as residual ash content (reduced to 6.29 %) and insufficient aromatization efficiency during oxidative cracking. These findings establish a technical foundation for high-value resource recovery from municipal sludge while addressing critical challenges in waste-to-product conversion.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107504"},"PeriodicalIF":6.2,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic and mechanism analysis of thermal decomposition of hexafluorobisphenol A-containing polyarylates","authors":"Xiubo Long ,&nbsp;Zhoufeng Wang ,&nbsp;Wenlong Yao ,&nbsp;Wenchi Zhang ,&nbsp;Puxi Zheng","doi":"10.1016/j.jaap.2025.107512","DOIUrl":"10.1016/j.jaap.2025.107512","url":null,"abstract":"<div><div>This research thoroughly examined the kinetics of thermal decomposition as well as the pyrolysis mechanism of a fluorinated polyarylate (PBR-F). From thermogravimetric analysis (TG), it was found that PBR-F-50 and PBR-F-80, which had a high content of hexafluorobisphenol A (BPAF), had a three-stage thermal decomposition characteristic, while on the contrary, PBR-F-20, which had a low content of BPAF monomer units, had only one stage. The kinetic assessment of thermal decomposition was conducted using the Friedman, Flymn-Wall-Ozawa (F-W-O), Kissinger-Akahira-Sunose (K-A-S), and integral Master-Plot techniques. Ultimately, the average activation energies for PBR-F-20, PBR-F-80 Stage 1, and PBR-F-80 Stage 2 were found to be 187.35 kJ/mol, 214.27 kJ/mol, and 271.26 kJ/mol, respectively. In addition, the pyrolysis mechanism function for PBR-F-20 and PBR-F-80 Stage 1 was F₁, while that for PBR-F-80 Stage 2 was R₂. By analyzing the thermally decomposed gaseous compounds of PBR-F and demonstrated that the polar functional group –CF₃ weakens the stability of the ester group and makes it more susceptible to bond breakage. However, some BPAF segments broke first and absorbed a lot of energy, delaying the breakage of the polymer backbone. The remaining segments were gradually and steadily released from the polymer as the temperature increased, thereby enhancing the thermal stability of PBR-F. Through thermal decomposition kinetics and mechanism analysis, the mechanism of two-stage pyrolysis for a novel fluorinated polyarylate (PBR-F) was revealed.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107512"},"PeriodicalIF":6.2,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal-driven release of harmful and potentially harmful constituents (HPHCs) in electrically heated tobacco products (eHTPs) aerosols: A comparative study of central vs. peripheral heating modes","authors":"Qi Zhang ,&nbsp;Zhiqiang Li ,&nbsp;Le Wang ,&nbsp;Zilong Zhang ,&nbsp;Ping Lei ,&nbsp;Xia Zhang ,&nbsp;Ke Zhang ,&nbsp;Xiangyu Li ,&nbsp;Xiaofeng Wang ,&nbsp;Bin Li ,&nbsp;Jingmei Han ,&nbsp;Lili Fu","doi":"10.1016/j.jaap.2025.107503","DOIUrl":"10.1016/j.jaap.2025.107503","url":null,"abstract":"<div><div>Electrically heated tobacco products (eHTPs) are designed to reduce harmful and potentially harmful constituent (HPHC) emissions compared to conventional cigarettes by operating below tobacco combustion thresholds. However, the temperature-dependent release mechanisms of HPHCs under different heating modes remain poorly characterized. The thermal release dynamics of 16 priority HPHCs (e.g., CO, NO, aldehydes, TSNAs, VOCs) in eHTP aerosols generated by central and peripheral heating modes were investigated. The results revealed a critical temperature range (275–300°C for peripheral heating mode; 325–350°C for central heating mode), beyond which HPHC emissions increase due to intensified pyrolysis. Notably, peripheral heating exhibits higher heating uniformity, leading to 2.5–5.8-fold higher HPHC yields than central heating at equivalent temperatures. Multivariate clustering analysis further identifies distinct emission patterns: stepwise increases under central heating versus abrupt surges under peripheral heating. These findings establish quantitative temperature-emission relationships and provide actionable guidelines for optimizing eHTP designs to minimize toxicant release while maintaining nicotine delivery.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107503"},"PeriodicalIF":6.2,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidative torrefaction-modulated preparation of biochar supported Ni catalysts for catalytic cracking of bio-oil heavy fractions","authors":"Zhiyuan Zhang,&nbsp;Feihao Shen,&nbsp;Xingwang Xi,&nbsp;Shuping Zhang","doi":"10.1016/j.jaap.2025.107496","DOIUrl":"10.1016/j.jaap.2025.107496","url":null,"abstract":"<div><div>Addressing global warming and fossil fuel scarcity necessitates the valorization of biomass waste. This study developed a high-performance biochar supported Ni catalyst derived from nut shells via oxidative torrefaction pretreatment coupled with carbothermal reduction, targeting the low-temperature catalytic cracking of bio-oil heavy fractions. Results show that the oxidative torrefaction process significantly increased the phenols content in bio-oil produced by subsequent carbothermal reduction, while simultaneously reducing the content of furans. Simultaneously, the oxidative cross-linking degree of the carbon-based catalyst precursor was enhanced by oxidative torrefaction, the carbon skeleton structure was effectively regulated, and the catalyst's specific surface area was increased by 15 % (516 m²/g). Critically, oxidative torrefaction pretreatment markedly reduced the size of active Ni⁰ particles (from 30.27 nm to 19.75 nm), improved their dispersion, strengthened metal-support interaction, and increased the number of surface-active sites and oxygen-containing functional groups. Benefiting from these structural advantages, the optimized catalyst demonstrated outstanding performance in low-temperature (550 ℃) catalytic cracking of bio-oil heavy fraction, achieving a high conversion ratio of 77.83 % for bio-oil heavy fraction. Meanwhile, cyclic stability tests on the same catalyst Ni@C-250–20 % showed its catalytic efficiency gradually decreased with increasing number of cycles, yet remained at 69.32 % after five cycles. This work validates oxidative torrefaction as an effective strategy, offering a novel approach for designing low-cost, sustainable biochar supported metal catalysts for efficient low-temperature catalytic cracking of bio-oil heavy fraction.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107496"},"PeriodicalIF":6.2,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on using biomass waste pyrolytic char as silicon reducing agent: In-depth comparison with the ideal forestry charcoal","authors":"Bichu Yin ,&nbsp;Haolin Li ,&nbsp;Zijie Li ,&nbsp;Xingwei Yang ,&nbsp;Guoqiang Lv ,&nbsp;Anqing Zheng ,&nbsp;Zhengjie Chen ,&nbsp;Yongsheng Ren ,&nbsp;Shaoyuan Li ,&nbsp;Wenhui Ma","doi":"10.1016/j.jaap.2025.107499","DOIUrl":"10.1016/j.jaap.2025.107499","url":null,"abstract":"<div><div>Biomass waste materials are abundantly available resources for producing pyrolytic char and have the potential to partially substitute forestry charcoal as carbonaceous reducing agent for silicon smelting. However, successful use of biomass waste pyrolytic char as silicon reducing agent has not been realized up to date. In order to reveal the fundamental factors that restrict the use of biomass waste pyrolytic char as an alternative to charcoal for silicon smelting, this study adopted sugarcane bagasse (SCB) as the representative of biomass material and pine wood (PW) as forestry wood for respectively preparing biochar and charcoal, and conducted in-depth comparison between them in terms of silicon reducing agent properties and pyrolytic mechanism. The experimental results show that pyrolysis temperature is the key factor that influences the properties of pyrolytic char from both biomass waste and forestry wood. At the pyrolysis temperature of 500℃, biomass pyrolytic char is superior to forestry charcoal in terms of char yield (30.41 wt% for SCB char, 26.73 wt% for PW charcoal at 500 ℃) and CO₂ gasification reactivity (R_0.5=0.054 for SCB char, 0.035 for PW charcoal) due to its far higher content of alkaline and alkali earth metals (AAEMs), and the electrical resistivity of biomass pyrolytic char approaches that of forestry charcoal (≥5700 μΩ·m), which could meet the properties of silicon reducing agent. However, biomass pyrolytic char is inferior to forestry charcoal in fixed carbon content, heat value, energy density, pore structure and mechanical strength, which might be the very reasons that restrict the use of biochar as an alternative to forestry charcoal as silicon reducing agent. Pyrolytic mechanism analysis reveals that the higher content of AAEMs in biomass wastes makes its pyrolytic mechanism somewhat different from that of forestry wood: SCB char was formed more easily at lower average activation energy (186.52 kJ·mol⁻¹) than charcoal (223.98 kJ·mol⁻¹), dehydration reaction precede the cleavage of C-H groups, and the decarbonylation and condensation reactions induced coking process start at lower temperature than that of PW, leading to the formation of more char and low molecular oxygenates. This research will provide theoretical guidance for the property optimization of biomass waste pyrolytic char as silicon reducing agent in the future work, promoting cleaner production of silicon by partial substitution of charcoal with biochar.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107499"},"PeriodicalIF":6.2,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuous pyrolysis of material recovery facility rejected municipal solid wastes using a fluidized bed reactor","authors":"Isabel Coffman ,&nbsp;Tien Pham ,&nbsp;Harish Radhakrishnan ,&nbsp;Sarah Tyree ,&nbsp;Keith Vorst ,&nbsp;Tannon Daugaard ,&nbsp;Xianglan Bai","doi":"10.1016/j.jaap.2025.107501","DOIUrl":"10.1016/j.jaap.2025.107501","url":null,"abstract":"<div><div>Material recovery facility sorting is currently one of the primary methods for recycling co-mingled municipal solid waste. After the recyclable waste fraction is sorted out and sold for profit, the residue, highly contaminated, co-mingled organic and plastic waste, is rejected and typically sent to landfills. In this study, material recovery facility-rejected waste was further sorted into a plastic rigid waste stream, a plastic film waste stream, and an organic waste stream, and pyrolyzed as an individual stream or co-pyrolyzed in a fluidized bed reactor equipped with four-stage fractionation condensers. The sorted plastic waste streams were rich in polyolefins with low ash. The pyrolysis of the plastic rigid waste stream yielded up to 68.1–70.3 % of condensables rich in hydrocarbons and 1.5–3.3 % chars with high heating values. In contrast, the organic waste stream contained high ash and oxygen, producing lower yields of acidic condensables with high moisture and higher yields of oxidized char with high ash content. The pyrolysis of mixed streams produced 53.1–59.4 % of higher quality condensables characterized by higher heating values and lower acidity. Especially, the condensables collected at the first two condensers were primarily comprised of hydrocarbon waxes with the higher heating values of 47.5–48.5 MJ/kg. It shows that synergistic interactions between the hydrogen-rich plastic and oxygen-rich organic wastes during their co-pyrolysis were catalyzed by high inorganic compositions in the waste streams, enhancing cracking reactions and reducing water. The inorganic impurities also migrated into chars and condensables, although the majority of inorganics remained in chars. Overall, this study examined the utilization potential of the landfilled waste rejected from current waste recycling industries.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107501"},"PeriodicalIF":6.2,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic enhancement of dechlorination and hydrochar performance via co-hydrothermal carbonization of textile dyeing sludge and garden waste","authors":"Zehua Zhao ,&nbsp;Yue Qiao ,&nbsp;Yi Wang ,&nbsp;Yang Lv ,&nbsp;Dapeng Zhang ,&nbsp;Houhu Zhang ,&nbsp;Yuanqing Bu ,&nbsp;Chenyu Wang","doi":"10.1016/j.jaap.2025.107502","DOIUrl":"10.1016/j.jaap.2025.107502","url":null,"abstract":"<div><div>Textile dyeing sludge (TDS) poses a challenge for both disposal and resource utilization. This study investigates the co-hydrothermal carbonization (co-HTC) of TDS and garden waste (GW) to promote the dechlorination of TDS and enhance the properties of derived hydrochar. TDS was mixed with GW in different ratios and reacted at 180°C to 260°C for 2–6 h. The dechlorination rate (DE) for TDS under standalone HTC was 7.79 %, whereas co-HTC with GW markedly increased the DE to 46.39 % – 66.78 %. Under appropriate HTC conditions and GW mix ratios, the DE increased by 11.9 % – 26.5 % compared with the theoretical value expected solely from the “dilution effect” of GW, indicating that synergistic dechlorination effect occurred between the components of GW and TDS, which further enhanced chlorine removal. Furthermore, considering typical downstream utilization scenarios of hydrochar, the influence of co-HTC on hydrochar performance was assessed in terms of fuel and adsorption properties. Co-HTC enhances the volatile matter and carbon content of the hydrochar, improving its fuel performance, the HHV increased from 10.42 MJ/kg to 18.14 MJ/kg, the volatile content increased from 54.55 % to a maximum of 75.80 %. Although the addition of GW partially obstructs the hydorchar’s porous structure, it also increases the amount of oxygen-containing functional groups, adsorption kinetics for two representative pollutants further demonstrated the altered adsorption behavior of co-HTC-derived hydrochar. Especially, the equilibrium adsorption amounts for MB increased from 32.80 mg/g to 45.99 – 52.97 mg/g. Overall, these findings provide new insights into the effective management of TDS through co-HTC with GW, highlighting its potential for resource recovery and environmental remediation.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107502"},"PeriodicalIF":6.2,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Staged KHCO3 pyrolysis of Clausena lansium seeds: Correlating thermal parameters with hierarchical carbon electrodes for enhanced capacitive energy storage","authors":"Qing Xu ,&nbsp;Shenwei Zhang ,&nbsp;Xuanyuan Ni ,&nbsp;Yunxing Zhao ,&nbsp;Denian Li ,&nbsp;Haoran Yuan","doi":"10.1016/j.jaap.2025.107498","DOIUrl":"10.1016/j.jaap.2025.107498","url":null,"abstract":"<div><div>This study develops a staged pyrolysis protocol using KHCO₃ activation under inert nitrogen atmosphere to convert agricultural waste (Clausena lansium seeds) into hierarchical porous carbon. By precisely controlling thermal conditions—pre-carbonization at 400 °C followed by dual-stage activation (300°C hold, then 800 °C)—with optimized solid-to-activator ratios, we establish a correlation between pyrolysis parameters and material properties. The process leverages KHCO₃’s staged decomposition for controlled pore evolution, yielding carbon matrices with microporous dominance (specific surface area 1366 m² g⁻¹, microporosity 84 %) while preserving structural coherence. Chemical characterization confirms oxygen-functionalized surfaces and enhanced graphitization via XPS and Raman analyses. Electrochemical validation using KOH electrolyte demonstrates superior capacitive behavior (346.3 F g⁻¹ at 1 A g⁻¹, 242.5 F g⁻¹ at 20 A g⁻¹) and cycling stability (100.9 % retention after 10,000 cycles). Symmetric supercapacitors deliver 8.96 Wh kg⁻¹ energy density at 250 W kg⁻¹, confirming applicability in energy storage systems. Our pyrolysis methodology provides an eco-compatible route to transform biomass into functional carbon materials without aggressive etching agents.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107498"},"PeriodicalIF":6.2,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From waste to watts: CoQDs on biochar as efficient catalysts for biomass-to-hydrogen conversion","authors":"Saimatun Nisa,&nbsp;Gaurav A. Bhaduri","doi":"10.1016/j.jaap.2025.107495","DOIUrl":"10.1016/j.jaap.2025.107495","url":null,"abstract":"<div><div>This study presents the design and application of cobalt quantum dots (CoQDs) supported on walnut shell-derived biochar as efficient catalysts for microwave-assisted biomass pyrolysis. Two catalyst formulations (Co-0.1 M and Co-0.5 M), with average CoQD sizes of 2.45 nm and 3.90 nm, respectively, were synthesized via an energy-efficient in situ microwave-assisted method. Comprehensive characterization (FTIR, Raman, XPS, XRD, SAED, SEM-EDX, and TEM) confirmed successful CoQD dispersion on the carbonaceous matrix. Thermogravimetric analysis coupled with iso-conversional models (FWO, KAS, ST) revealed a substantial reduction in activation energy—from 229.16 kJ/mol (non-catalytic) to 200.64 kJ/mol and 146.42 kJ/mol for Co-0.1 M and Co-0.5 M, respectively. Kinetic compensation effects and mechanistic analyses using the Achar and Criado master plots indicated mixed nucleation and diffusion-controlled degradation. Catalytic pyrolysis at 600 °C significantly enhanced pyro-gas yield (from 52 % to 75 %) and increased hydrogen content in the gas phase (from 5 % to 25 %). GC-MS and GC analyses revealed enhanced formation of phenolic compounds and gasoline-range hydrocarbons in the bio-oil. These results underscore the potential of CoQDs-functionalized biochar as a cost-effective catalyst for selective, energy-efficient biomass valorization via microwave pyrolysis.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"194 ","pages":"Article 107495"},"PeriodicalIF":6.2,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}