Molecular Catalysis
·
2023
·
IF 4.6
Tiantian Zhang,Jiacheng Xu,Yan Sun,Shiyu Fang,Zuliang Wu,Erhao Gao,Jiali Zhu,Wei Wang,Lianxin Dai,Weihua Liu,Buhe Zhang,Junwei Zhang,Shuiliang Yao,Jing Li
Nano-Au has a good catalytic activity for CO oxidation, but its catalytic mechanism is still not clear. Here, CO oxidation on Au 2 O 3 and its thermal decomposition products were studied using thermogravimetric-mass spectrometry (TG-MS) and operando diffuse reflectance infrared Fourier transform spectroscopy-mass spectrometry (DRIFTS-MS) to explore the key active components of Au catalyst for CO oxidation. The TG-MS results showed that Au 2 O 3 decomposed to AuO at 210 °C and Au at 375 °C and was oxidized to form Au oxide above 375 °C. When Au 2 O 3 decomposed into Au x O y (x>y) above 210 °C, the CO oxidation activity obviously increased. Au atoms in the Au-Au system serve as electron donor and CO adsorption sites. Au atom is oxidized to AuO by the O atom from O 2 decomposition following the Epling-Xu decomposition mechanism. A schematic diagram of the key components of Au 2 O 3 catalysts during CO oxidation was proposed based on TG-MS and operando DRIFTS-MS analysis results.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Yueping Liu,Suning Li,Yongcheng Yang,Yongxiang Liang,Fei Wang,Xuetong Li,Deng Zhao,Yanjun Lu,Hui Liu,Shuai Guo
The aim of this study is to investigate the role of different carbon-based structures on the pyrolysis pathway and gas product distribution of polypropylene (PP). Using in situ DRIFTS coupled with thermogravimetric mass spectrometry, this study investigated the synergistic mechanisms between polypropylene (PP) and common plastics and biomass at the molecular level. The following mechanisms were revealed: 1) Polyethylene erephthalate (PET) induces demethylation of PP through oxygenated fragments, which weakens the stability of its main chain and synergistically reduces the pyrolysis temperature. The high-temperature polyene structure of polyvinyl chloride (PVC) promotes further breakage of the PP main chain, synergistically driving the directional conversion of gas products to unsaturated hydrocarbons and chlorine-containing compounds. The phenyl groups in polystyrene (PS) trigger PP activation at low temperatures, improving the yield of toluene gas. 2) PP inhibits the decomposition of blended components through physical entanglement at low temperatures. At high temperatures, polyenes, phenyl groups and other cleavage products reorganize with PP hydroxyl fragments, promoting the enrichment of olefins, aromatics and chlorinated compounds. 3) In PP-biomass systems, it is hypothesized that the PP pyrolysis pathway is altered, enhancing the selectivity for short-chain hydrocarbons and monocyclic aromatics. This effect is likely mediated through ash-catalyzed reactions and induction by oxygen-containing fragments. This study employs in situ Fourier-transform infrared (FTIR) spectroscopy to monitor in real time the molecular-level evolution of PP-based mixed waste plastics and biomass pyrolysis, revealing fundamental carbon-chain structure-property relationships. These findings establish a mechanistic framework for the rational design of high-efficiency pyrolysis systems with precisely controlled product distributions through synergistic interactions.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Mengqi Zhong,Jinping Li,Lun Zhou,Teng Wang,Jingxin Liu,Meng Mei,Si Chen
This research investigates the mechanism of co-pyrolysis in waste-blended textiles (polyester/cotton blends). Thermogravimetry and mass spectrometry analysis were utilized to study the mass loss behavior and gas emission characteristics of cellulose (CE) and polyethylene terephthalate (PET) with various mass ratios during pyrolysis. The EA, BET and FTIR analysis were used to investigate the interaction among the solid phase products. The findings revealed a clear synergistic effect between CE and PET. When the theoretical and actual thermogravimetry/gas release curves were compared, the synergistic effect in the co-pyrolysis process inhibited a release of small volatile substances (H 2 , CH 4 , C 2 H 2 , CO and CO 2 ) at high temperatures and directly promoted hydrocarbon enrichment in solid products, which could affect the adsorption performance of solid phase products, and the inhibition effect was strongest when the ratio was 35:65.
研究领域:
能源与环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Rongbin Li,Kai Wei,Qian Huang,Hongde Xia
The unburnt carbon content of fly ash is an important index for evaluating the combustion efficiency of boilers. Measurement by traditional loss-on-ignition (LOI), approximate and elemental analyses causes large errors due to mixing minerals such as portlandites, carbonates, or sulfates with the unburnt carbon. In this paper a new method of Equivalent Characteristic Spectrum Analysis (ECSA®) based on Thermogravimetric Mass Spectrometry (TG-MS) was adopted to determine the unburnt carbon in fly ash. The measuring mechanism, accuracy, superiority, sensitivity, and reliability of ECSA® were discussed. The intrinsic measuring mechanism of ECSA® and its sensitivity were explored through analyzing the reaction characteristics of model compounds that were used to simulate the real fly ash. Five types of real fly ashes collected from boiler plants were used to calibrate and verify the reliability and accuracy of ECSA® method. The ECSA® was finally validated to be more precise and accurate by improving 2 to 3 orders of magnitude in error compared with the LOI and elemental analysis on determining the unburnt carbon in fly ash, and can provide reliable information to assess the operating status of boilers.
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
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2025
·
IF 6.2
Longfei Wang,Yuanjun Tang,Guoneng Li,Jun Dong,Yao Fang,Wenwen Guo,Chao Ye
This study systematically investigates the effects of Fe-loading on the pyrolysis behavior of three key biomass components: cellulose , xylan , and lignin . Complementary analytical techniques, thermogravimetric analysis (TGA), thermogravimetry-mass spectrometry (TG-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), were utilized to assess the impact of Fe-loading on: ( i ) pyrolysis characteristics, ( ii ) the combined pyrolysis index ( CPI ), ( iii ) small-molecule gas evolution, and ( iv ) tar product distribution. Results demonstrate that the loading of Fe(NO 3 ) 3 significantly reduced the initial pyrolysis temperatures of cellulose and xylan by ∼140 °C and ∼62 °C, respectively, resulting in 58 % and 37 % decreases in CPI values. Conversely, lignin exhibited a 111 % CPI increase under Fe loading conditions, attributable to accelerated aryl-ether bond cleavage. The presence of Fe enhanced CO 2 evolution while suppressing H 2 O and CO generation in cellulose / xylan conditions. In contrast, it promoted CH 4 , H 2 , CO, and CO 2 evolution during lignin pyrolysis. Py-GC/MS analysis indicated that the presence of Fe drives aromatization through deoxygenation pathways while inhibiting ring-opening depolymerization, consequently shifting tar composition toward higher-carbon-number aromatic hydrocarbons. The findings can serve as a valuable reference for the application and promotion of the high-value valorization of waste biomass.
研究领域:
生物能源
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生物质转化
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热化学
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分析化学
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 8
·期 1
·64-76
·
IF 5.2
Haosheng Xin,Haiyong Wang,Xiaohong Hu,Xiuzheng Zhuang,Long Yan,Chenguang Wang,Longlong Ma,Qiying Liu
Cellulose hydrolysis and further conversion to diketones and alcohols was performed with graphene layer encapsulated cobalt catalysts (Co@C) in phosphoric acid aqueous solution. A total of 60.5% yield of the products mainly including ethanol, 2,5-hexanedione (2,5-HD) and diols could be achieved in 0.06 M H3PO4 solution. A series of characterization methods such as XRD, XPS, TEM, TG-MS, BET, ICP, H2-TPD, NH3-TPD, and Raman were carried out to explore the catalyst formation mechanism and reaction activity. The results of the analysis indicated that the calcination temperature had a deep influence on the structure formation of the Co@C catalysts, thus leading to differences in the reaction activity. While the calcination temperature was determined at 700 °C, the Co@C catalyst meets with the requirements of optimal reaction activity, appropriate particle size, suitable surface area, and pore size. Besides, it was found that H3PO4 is not only favorable in cellulose hydrolysis but also cooperates with the Co@C catalyst in the hydrogenolysis of C–O bond and C–C bonds for the formation of products. This work provides a possible way for renewable cellulose conversion to diketone and alcohols over encapsulated non-noble metal catalyst combined with phosphoric acid aqueous solution.
研究领域:
化学工程
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催化
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2026
·
IF 6.7
Zheng-Zhi Zhang,Zhu-Fei Yang,Ya-Sen Wu,Zhan-Ku Li,Jing-Chong Yan,Wei-Dong Zhang,Zhi-Ping Lei,Shi-Biao Ren,Zhi-Cai Wang,Heng-Fu Shui
The unclear migration mechanism of organic sulfur during coal pyrolysis limits molecular-level understanding, hindering targeted desulfurization and clean utilization of high-sulfur coal. In this study, a "structural simplification" strategy was proposed, in which the thermal dissolution soluble fraction (TDSF) from Duizhen high-sulfur coking coal (DHSC) was employed as the research subject. This TDSF is characterized by its structural homogeneity and ash-free nature, thereby eliminating the interference caused by structural heterogeneity and ash. By combining TG-MS and ReaxFF-MD simulations, the abundant aliphatic structures in TDSF generate a strong "self-hydrogen supply" effect during the pyrolysis process. At 2800 K, the number of C-H bond cleavages in the DHSC/N 2 system is 167, whereas in the TDSF/N 2 system, it reaches as high as 258. The co-hydrogenation experiments of TDSF and DHSC with phenanthrene demonstrated that the hydrogen-donating capacity of TDSF was 1.64 times that of DHSC. The generated active hydrogen radicals selectively attack the C-S bonds in thiophene and sulfoxide, prompting a large amount of sulfur to migrate to the gas and liquid phases. The pyrolysis experiments showed that the sulfur removal rate of TSDF (37.39%) during pyrolysis was significantly higher than that of DHSC (30.08%). It was demonstrated that the desulfurization performance of DHSC can be further enhanced by the use of a hydrogen atmosphere and elevated pyrolysis temperatures. Based on these molecular-level insights, precise desulfurization strategies for high-sulfur coal pyrolysis can be formulated.
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Donghua Li,Feng Shi,Meihua Fu,Yi Lu,Can Liu,Xu Lin,Defa Hou,Hao Sun,Cuiping Luo,Zhifeng Zheng,Yunwu Zheng
To unveil the nitrogen migration and conversion characteristics, catalytic copyrolysis of biomass pseudo components and polyamide (PA) with different blend ratios (1:0, 5:1, 3:1, 1:1, 1:3, 1:5, 0:1) under an ammonia atmosphere was proposed to boost the yield of N-containing compounds (NCCs) and N-rich biochar. The evolution and distribution of NCCs in liquid, gas and biochar were systematically investigated with a combination of TG-MS, Py-GC/MS and EPR. Synergistic effects and possible reaction pathways were also evaluated. Experimental results showed that PA could obviously boost biomass conversion due to increasing the chance of secondary cleavage, and the comprehensive synergistic effect of biomass-derived H* radicals, acid sites of the catalyst and cracking reactions (-C-N and C-C bonds) that reduced the reaction energy barrier and enhanced the NH 3 and HCN yields. NH 3 comes from the amino acids that are released from the amino acid pyrolysis and hydrolysis of HCN on the surface of char, while HCN is from the secondary cracking of primary pyrolysis products. Adding biomass increased CO 2 , CO, CH 4 , C-O and C O emissions from co-pyrolysis. Additionally, significant synergetic effects were observed when Biomass/PA= 3:1, which improved the NCCs and pyridine yields by 78.58% and 48.23%, respectively, under the HZSM-5 catalyst. A lower proportion of PA addition facilitated the Maillard reaction and amide bond cleavage to enhance the NCCs content and suppressed π-conjugated ring structure compound evolution and coke-derived O-containing compound polymerization, while a higher content of PA was favorable for amine and diaza heterocycle compound formation. Moreover, the addition of PA reduced the HHV and N content in biochar, resulting in lower pyrrole-N content and graphitization degree due to secondary cross-polymerization reaction of reaction volatiles, but it enhanced the polarity due to higher oxygen content (14.98%).
研究领域:
能源与燃料
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）