Asia-Pacific Journal of Chemical Engineering
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2012
·Vol. 8
·期 4
·567-577
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IF 0.758
Ying Gu,Xiaowei Liu,Bo Zhao,Wenqiang Liu,Minghou Xu
Nitrogen species distribution during coal pyrolysis with Ca addition in N 2 , CO 2 and Ar was studied at 1000 °C using a horizontal tube furnace. In particular, the effect of Ca on the distribution of nitrogen species in N 2 and CO 2 atmospheres, which were closer to pyrolysis processes of conversional air and oxy-fuel combustion in comparison with inert Ar environment, was investigated for the first time in this work. It was found that Ca has a great effect on nitrogen species distribution during both coal and demineralized coal pyrolysis; on the other hand, CO 2 causes the formation of NO. Demineralization increases the formation of HCN and char nitrogen, but there is little effect on NH 3 formation during pyrolysis in N 2 , in contrast to pyrolysis in Ar atmosphere, which decreases NH 3 formation. A significant reduction in char yield was found after char gasification in CO 2 at 1000 °C. With two different Ca-based additives, i.e., (CH 3 COO) 2 Ca and Ca(OH) 2 , char yield decreases with the increasing amount of Ca additives in both cases. The effect of Ca on HCN and NH 3 formation during pyrolysis depends on both the form of Ca and the amount of addition. In most cases, HCN and NH 3 formation decreases with Ca addition in Ar, but increases in N 2 . Ca addition slightly promotes HCN formation during pyrolysis in CO 2 . There is no NH 3 detected during pyrolysis in CO 2 because of the reaction of NH 3 and CO 2 in the background. In addition, NO concentration decreases sharply with increasing the amount of Ca addition in the atmosphere of CO 2 , which means that Ca has an effect not only on pyrolysis, but also on gasification of char in CO 2 . In most cases, char nitrogen increases with Ca addition in N 2 or Ar. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Tianren Liu,Wensheng Zhang,Qingmei Tan,Weilong Lian,Haiting Lin,Jianshen Li,Dongxue Han,Yingying Fan,Dongdong Qin,Li Niu
Photocatalytic synthesis of ammonia (NH 3 ) from nitrogen (N 2 ) offers a promising strategy for carbon neutrality, as it avoids the energy-intensive and carbon-emitting industrial processes. The exploration of high-efficiency N 2 photofixation systems for photocatalytic N 2 reduction reaction (pNRR) is critical but it remains a challenge since the lack of rational structural design and atomic-level insights into molecular N 2 activation mechanism. Herein, an atomically dispersed single-atom palladium (Pd) active sites decorated oxygen-deficient molybdenum oxide (Pd/MoO 3-x ) was creatively designed for assessing pNRR performance. Interestingly, the integration of single-atom Pd active sites in MoO 3-x can significantly weaken the N≡N bond of adsorbed N 2 and effectively lower the activation energy barrier during the pNRR process. This is attributed to the fact that the modified Pd single-atom sites of Pd/MoO 3-x play a dominant role in the N 2 spontaneous adsorption process as well as possess a remarkable photogenerated electron trapping ability, which could be assisted to inject electrons into N 2 antibonding orbital, thus significantly accelerates the reaction kinetics. Consequently, the Pd/MoO 3-x photocatalyst reaches an impressive NH 3 yield rate of 103.2 μgg cat . −1 h −1 , which is superior to that of pristine MoO 3-x (21.2 μgg cat . −1 h −1 ) and commercial MoO 3 (6.5 μgg cat . −1 h −1 ), respectively. The present study not only creates a reliable approach to expand efficient N 2 photofixation system under mild conditions through the fabrication of atomically dispersed monometallic active sites, but also offers atomic-level insights into the underlying mechanism of pNRR catalytic process.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Zhiwei Zhao,Yuan Li,Yanjie Wang,Yating Wang,Yuhao Tang,Mengyue Lu,Xu Yang,Xiaoqing Wang,Feifei Zhang,Jinping Li,Jiangfeng Yang
The enrichment of low-concentration coal-bed methane is beneficial to solving the world’s energy concerns. However, most adsorbents used for CH 4 /N 2 separation from coal-bed methane are hydrophilic and ineffective under humid conditions. In this study, a hydrophobic nickel-based metal–organic framework (TUTQ-1Ni) was developed for efficient CH 4 /N 2 separation under humid conditions. Adsorption results show that, at 298 K and 1 bar, TUTQ-1Ni exhibits the highest CH 4 /N 2 selectivity (11.0) among the reported hydrophobic CH 4 -selective metal–organic frameworks. The results of theoretical calculations reveal that multiple O/S sites provide strong adsorption affinity for CH 4 over N 2 . Further, breakthrough experiments confirm the suitability of the material for CH 4 /N 2 separation, with the separation performance being maintained at even a high relative humidity of 100 %. The pressure swing adsorption simulation results indicate that TUTQ-1Ni is a potential candidate material for the selective capture of methane from coal-bed methane.
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FUEL
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2024
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IF 6.7
Kai Zhang,Rui Zhang,Yuxin Cui,Jiayin Shang,Xueling Wei,Sumin Wang,Siqin Jia,Ke Qin,Haiyan Zhang,Hongyan Wang,Taotao Ai,Qiguan Wang
The electrocatalytic nitrogen reduction reaction (NRR) to synthesize ammonia is an important and challenging task in chemistry, where low-cost, highly active non-metallic catalysts such as boron carbonitride (BCN) are still highly desired. Tuning the electronic environment of the active site B is an effective approach to improve the NRR performance of BCNs. However, the study on the mechanism of this effect has been seriously neglected. The diversity and controllability in atomic arrangements of BCN make it suitable for studying the relationship between the local chemical environment of boron and the catalytic properties. To this end, we design four kinds of BCN materials named as homogeneous BCN nanoribbon and BCN nanosheet enriched with B − C active sites and localized phase-separated BCN nanoribbon and BCN nanosheet rich in B − N active sites, and theoretically screen the homogeneous type BCN nanoribbons that have better NRR performances. Meanwhile, we experimentally demonstrate that the optimized charge redistribution of B atoms in BCN skeleton by tuning the electronic environment makes the B − C sites being the effective centers in NRR, and arising the excellent NH 3 productivity of 63.02 μg h −1 mg − 1 cat with a highest Faraday efficiency of 32.28 %.
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SURFACE & COATINGS TECHNOLOGY
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2024
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IF 5.3
Tongguo Huo,Dan Zhu,Jianxin Zheng,Yuan Lin,Yu Dai,Jian Wu
This study systematically investigated for the first time the effects of varying the temperature, pressure, C/Si molar ratio, and H 2 /Si molar ratio on β-SiC coatings produced via chemical vapor deposition (CVD) using the SiCl 4 –CH 4 –H 2 –N 2 system. Thermodynamic theoretical calculations were performed using the HSC Chemistry software. The temperature and C/Si molar ratio considerably affected the morphology, phase, and composition of β-SiC coatings. High-quality β-SiC coatings along the (111) crystal plane exhibiting a uniform surface, high density, low roughness, and good crystallinity were successfully synthesized at 1523.15 K and 200 Pa with a C/Si molar ratio of 1.0 and H 2 /Si molar ratio of 6.5. Additionally, when N 2 was used as the dilution gas instead of Ar, the resulting β-SiC coatings demonstrated reduced roughness, fewer free carbon, increased hardness (37.05 GPa vs. 39.19 GPa), enhanced modulus of elasticity (237.26 GPa vs. 264.24 GPa), and superior coating adhesion (16.48 MPa vs. 18.29 MPa).
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POLYMER
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2025
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IF 4.5
Shuang Wang,Dudu Li,Zelong Xu,Fan Zhou,Zhihua Qiao,Zibo Yang,Zhi Wang
Coordination polymer (CP) glasses offer high processability and permanent accessible pores, having promising potential in gas separation. However, their low porosity makes it difficult to prepare high-performance gas separation membranes. In this work, we combined the advantages of CP glasses and inorganic fillers, and selected ag Zn-P-dmbIm as the continuous phase and hydroxylated multi-walled carbon nanotubes (HMWCNTs) as the dispersed phase to prepare HMWCNTs/ ag Zn-P-dmbIm mixed matrix membranes (MMMs). The very favorable interfacial compatibility and excellent CO 2 /N 2 gas separation performance of the MMM-2 membrane were demonstrated by a series of characterizations. The test results revealed that the CO 2 permeability and ideal CO 2 /N 2 selectivity of MMM-2 membrane were 9776.8 Barrer and 31.1, respectively, which exceeded the Robeson 2019 upper bound. In addition, the well-defined long-term stability of the MMM-2 membrane lays the foundation for realizing gas separation membranes for industrial applications in practice. This provides a strategy for the subsequent preparation of CP glasses-based MMMs.
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INDUSTRIAL CROPS AND PRODUCTS
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2026
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IF 6.4
Xujuan Huang,Tong Liu,Yujian Zhang,Xuexuan Zhou,Qunqun Bian,Yongyang Cheng,Zhaosheng Cai
The MPAN-g-HEC product exhibits CO 2 responsiveness. • CO 2 gas protonates MPAN-g-HEC to MPAN + -g-HEC. • MPAN + -g-HEC can enhance the stability of CNF-based Pickering emulsion. • Alternating CO 2 and N 2 in the system switches the emulsification and separation. Cellulose has been widely used in conventional Pickering emulsions, yet its application in stimulus-responsive Pickering emulsions remains relatively limited. In this paper, cellulose-based CO 2 /N 2 stimuli-responsive polymer compounds (MPAN-g-HEC) were prepared through the hydrophobic modification of hydroxyethyl cellulose using the maleopimaric acid 2-dimethylaminopropylamine imide with a tertiary amine group (MPAN). The grafting rate of MPAN-g-HEC was controlled by adjusting the HEC-to-MPAN mass ratio. Specifically, five grafted products (MPAN-g-HEC I∼V) were prepared, and the grafting rate increased from 9.24% to 48.43%. The addition of CO 2 resulted in the protonation of MPAN-g-HEC, converting it to the MPAN + -g-HEC. The critical micelle concentration (CMC) values of MPAN + -g-HEC ranged from 0.28 to 0.88 g/L, with corresponding surface tensions of 40.8–43.3 mN/m. The product with the best performance (MPAN-g-HEC IV, abbreviated as MPAN-g-HEC) is used to enhance the stability of Pickering emulsions of cellulose nanofibers. These stimuli-responsive Pickering emulsions exhibit stability due to the electrostatic interactions between MPAN + -g-HEC and CNF, as well as the formation of interfacial films at the oil-water interface. In addition, the alternating passage of CO 2 and N 2 can achieve the interconversion between emulsification and demulsification, and the process is reversible. Rheological tests show that the G′ and G″ tend first to decrease and then increase, indicating that the Pickering emulsion first undergoes damage and then reforms a network structure. Download: Download high-res image (192KB) Download: Download full-size image
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Journal of Cleaner Production
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2026
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IF 10.7
Shanjian Liu,Wenjing Zhao,Weming Yi,Zhisen He,Jiawen Zhang,Haining Wang
This study investigates nitrogen-rich catalytic pyrolysis of cellulose in an N 2 /CO 2 atmosphere, focusing on the synergistic effects of catalysts and CO 2 on bio-oil composition. The results show that catalyst acidity governs product selectivity, markedly enhancing high-value nitrogen-containing compounds while suppressing carbonyl species. Among the catalysts tested, Al-MCM-41 exhibited the strongest promotion of nitrogen-containing compounds, increasing their relative content from 22.24% (without catalyst) to 88.83%. HZSM-5, Mo 2 C, and γ-Al 2 O 3 favored the formation of furans, esters, and sugars, whereas CO 2 facilitated biomass decomposition and altered product distribution. In addition, catalysts significantly regulated nitrogen heterocycles, increasing pyridine, pyrrole, and nitrile contents. Biochars obtained with HZSM-5 and Al-MCM-41 showed abundant oxygen-containing functional groups, indicating improved pore structure development. These findings demonstrate an effective catalytic strategy for the selective conversion of biomass into high-value nitrogen compounds.
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Carbon Letters
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2026
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IF 6.2
Sheng Hongliang,He Tao,Li Ye,Cao Chengyang,He Song
Poplar wood was employed as the precursor to develop a coupled “microwave self-gasification & aqueous post-modification” protocol that enables instantaneous activation within a microwave field, yielding activated carbon dominated by ultra-micropores (< 0.7 nm). Despite a modest BET surface area of ~ 900 m²/g, the material exhibits an exceptional CO₂ uptake of 180.4 mg/g at 0 °C and 1 bar—1.6-fold higher than at 25 °C—while N₂ uptake remains below 30 mg/g under the same conditions. On a pore-volume basis, the carbon stores 443.79 mg CO₂ per cm³ at 0 °C and 278.62 mg/cm³ at 25 °C. CO₂ adsorption proceeds via a multilayer mechanism with the isosteric heat (Qst) decreasing from 45 to 23 kJ mol⁻¹, whereas N₂ follows a monolayer pathway with Qst held between 20 and 24 kJ mol⁻¹. IAST calculations reveal that CO₂/N₂ selectivity rises from 70 to 90 with increasing pressure at 0 °C and levels off around 50 at 25 °C. Dynamic breakthrough experiments deliver a separation factor of 8.28 for a 15% CO₂/85% N₂ mixture. GCMC simulations further indicate that O–C = O-functionalized surfaces confer the highest CO₂ capacity, while C–S–C motifs are the least favorable in competitive adsorption.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2017
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IF 3.615
Chang Wang,Jiaqi Liu,Jiangfeng Yang,Jinping Li
Synthesis of ultra-high silica (SiO 2 /Al 2 O 3 > 1800) MFI type zeolite such as silicalite-1 is still considered to be luxury because of the long synthesis time (5–12 days). Here, this material with a highly uniform mesoporous (20 nm) structure was crystallized in a shorter time (20 h) using a crystal-seeds method when an appropriate amount of potassium fluoride was added. Characterization techniques including XRD , SEM, TEM and liquid nitrogen adsorption provided detailed information on the two kinds of porous structure silicalite-1. Due to the “smooth” adsorption surface of silicalite-1 containing few equilibrium ions, it is ideal for the separation of gas mixtures containing non-polar molecules with similar physical properties. Moreover, the CH 4 , N 2 , CO 2 and C 2 H 6 adsorption properties were also investigated. Microporous silicalite-1 has a high adsorption capacity for CH 4 , N 2 , CO 2 and C 2 H 6 and adsorption selectivity for CH 4 /N 2 , CO 2 /N 2 , CO 2 /CH 4 and C 2 H 6 /CH 4 . Although a lower adsorption capacity was observed for mesoporous silicalite-1, the pore size did not affect the outstanding adsorption selectivity, on the contrary, the selectivity of mesoporous silicalite-1 was improved.
研究领域:
材料科学
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化学工程
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9.1
Xinzeng Xin,Weiliang Shi,Chao Li,Wenzhu Sun,Jingtao Zhang,Wuzhu Sun
With its diverse sources and strong mobility, nitrate has become one of the most common contaminants in natural water bodies worldwide, posing an increasingly serious threat to ecosystems and human health. The wide spatial distribution of nitrate pollution makes traditional centralized treatment techniques (e.g., biological denitrification and reverse osmosis) impractical. Here, we address this challenge by developing an easily deployable decentralized system coupling a self-powered aluminum-nitrate (Al-NO 3 − ) battery with chemical reduction. The metal Al anode undergoes controlled oxidation, and the spontaneously generated electrons drive nitrate reduction to nitrite at the surface-reconstructed silver mesh (SRSM) cathode. The driving force originates from the potential difference between electrodes, requiring no external power supply. A proton exchange membrane physically separates the chambers, completely avoiding aluminum ion leakage and secondary pollution, while dissolved Al precipitates into recyclable aluminum hydroxide. Sodium ascorbate addition suppresses hydrogen evolution reaction at the Al surface, increasing utilization efficiency from 3.54% to 33.69%. Subsequently, the nitrite is quantitatively converted to N 2 by reduction with sulfamic acid. The system achieves highly selective conversion of nitrate to benign N 2 . Notably, the system operates efficiently in real water bodies (tap, lake, and groundwater) without requiring supporting electrolyte addition, achieving up to 94% nitrate removal and 99% N 2 selectivity. Long-term testing demonstrates that removal rate remains above 70% and N 2 selectivity is near perfect after 20 operating cycles. This off-grid, green technology provides a practical decentralized remediation solution for widespread nitrate pollution.
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WATER RESEARCH
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2017
·
IF 6.942
Youzhi Ji,Jing Bai,Jinhua Li,Tao Luo,Li Qiao,Qingyi Zeng,Baoxue Zhou
A highly selective method for transforming ammonia nitrogen to N 2 was proposed, based on a novel solar-driven photoelectrocatalytic-chlorine radical reactions (PEC-chlorine) system. The PEC-chlorine system was facilitated by a visible light response WO 3 nanoplate array (NPA) electrode in an ammonia solution containing chloride ions (Cl − ). Under illumination, photoholes from WO 3 promote the oxidation of Cl − to chlorine radical (Cl ). This radical can selectively transform ammonia nitrogen to N 2 (79.9%) and NO 3 − (19.2%), similar to the breakpoint chlorination reaction . The ammonia nitrogen removal efficiency increased from 10.6% (PEC without Cl − ) to 99.9% with the PEC-chlorine system within 90 min operation, which can be attributed to the cyclic reactions between Cl − /Cl and the reaction intermediates (NH 2 , NHCl, etc.) that expand the degradation reactions from the surface of the electrodes to the whole solution system. Moreover, Cl is the main radical species contributing to the transformation of ammonia nitrogen to N 2 , which is confirmed by the tBuOH capture experiment. Compared to conventional breakpoint chlorination , the PEC-chlorine system is a more economical and efficient means for ammonia nitrogen degradation because of the fast removal rate, no additional chlorine cost, and its use of clean energy (since it is solar-driven).
研究领域:
环境科学
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光电催化
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水处理
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可再生能源
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化学工程
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