Materials Research Express
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2020
·Vol. 7
·期 11
·115502
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IF 1.929
Jie Zhang,Dandan Li,Jianping Qiu,Zhengru Wen,Xiaohui Luo,Chaoqun Bian,Jian Chen,Mengfei Luo
Photocatalytic degradation of triclosan is one of the most promising way to eliminate triclosan pollution in water, yet it presents profound challenges to develop efficient photocatalysts to meet the demand of application. Herein, we demonstrate a facile hydrothermal-precipitation method to prepare amorphous Nb2O5 catalysts by using niobium(V) oxalate hydrate and ammonium carbonate. A series of amorphous Nb2O5 catalysts were obtained and analyzed by detail characterizations (XRD, XPS, BET and SEM). By optimizing synthesis conditions, it was found that 180/12-Nb2O5-(1:5) catalyst exhibited the optimal photocatalytic activity for triclosan degradation. Furthermore, the pseudo-first-order kinetic equations for triclosan degradation over 180/12-Nb2O5-(1:5) catalyst were investigated under conditions with different pH value. Among them, the triclosan degradation rate over 180/12-Nb2O5-(1:5) catalyst gave the highest reaction constant k (0.5 min−1) and shortest half-period (t1/2 = 0.17 min−1) at pH of 8. The presence of ionic state triclosan in base condition should be responsible for the improved degradation rate from acid to base reaction condition. Compared with molecular triclosan, ionic state triclosan exhibits very high reaction rate with radicals due to its strong electrophilic property. The high photocatalytic activity of 180/12-Nb2O5-(1:5) catalyst should be related to the presence of amorphous structure compared with calcined 180/12-Nb2O5-(1:5) catalyst with highly crystalline structure. The existence of N species doping and nano-sheet structure in catalyst is also thought to promote the catalytic reaction.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 5
·1662-1670
·
IF 9.48
Wenjing Song,Yanyan He,Sitong Lai,Weikun Lai,Xiaodong Yi,Weimin Yang,Xingmao Jiang
It is a challenge to promote aqueous-phase precise conversion of renewable lignin to valuable chemical building blocks via engineering transition metal catalysts. Motivated by the water effect in promoting catalytic activity, a Ni/Nb2O5 catalyst assembled from plenty of Nb2O5 nanoplates enabled efficient selective hydrodeoxygenation of lignin-derived phenols to alcohols in the aqueous phase. Taking advantage of hierarchical plate features, the interactions between Ni and Nb2O5 plates were enhanced, with the generation of additional interfacial Ni–NbOx sites. The presence of water significantly enhanced the selective hydrodeoxygenation performance by promoting hydrogenation and hydrolysis, and retarding the dehydration process. Through this strategy, the overall yields of alcohols for lignin oil upgrading reached 73.5 wt% in water at 220 °C.
研究领域:
化学工程
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催化科学
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可再生资源转化
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Yu Ling,Xiao Chen,Hongkai Tong,Weixiang Guan,Ping Chen,Zhaohui Huang,Changhai Liang
Propylene dimerization is an attractive way to branch out the bulk chemicals to high-value-added fine chemicals. Based on the coordinatively unsaturated surface sites of nickel and solid acid sites for boosting highly selective dimerization of propylene, a series of NiSO4/Nb2O5 catalysts were synthesized by tuning the synergistic effect through adjusting the calcination temperatures. Under the conditions of 70 °C, 2.5 MPa, and LHSV = 3 h–1 in a fixed-bed reactor, the NiSO4/Nb2O5-400 catalyst exhibits the highest propylene conversion of ca. 89% with 75% selectivity to C6 products (mainly including 4-methyl-2-pentene and 3-hexene). A possible Cossee–Arlman pathway has been proposed for the dimerization of propylene. In the long-term stability testing, an induction period has been observed, which may be attributed to the coordination of propylene molecules to unsaturated Ni2+ cations generating some active nickel species. Subsequently, the NiSO4/Nb2O5-400 catalyst presents a stability up to 30 h. The interesting results inspired us to modulate the interaction of metal (salt) and acid sites to strengthen the selective dimerization of low-carbon olefins.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Shitong Yu,Pan Xu,Zhicheng Luo
Converting lignin into renewable fuels via hydrogenolysis is crucial for achieving carbon neutrality. Existing methods primarily produce monomers in the carbon range of 6–9, inadequate for sustainable aviation fuels requiring heavier components. This study introduces a Ni/Nb 2 O 5 catalyst for catalytic transfer hydrogenolysis of organosolv birch lignin with isopropanol, predominantly resulting in dimers and trimers within carbon ranges of 8–16 and 16–30, comprising 24.7 % and 60.5 % of the lignin-oil, respectively. The catalyst's oxygen vacancies and acid sites facilitate efficient C-O and C-C bonds cleavage, preserving a highly aromatic structure with reduced O/C ratio, elevated H/C ratio, and decreased unsaturation. Characterization techniques confirm a significant 55.5 % deoxygenation degree of the lignin-oil, making it suitable for the synthesis of customized fuel across various carbon numbers. This approach offers a practical pathway for obtaining renewable heavier fuel components and precursors from lignin, significantly advancing sustainable fuel technologies.
研究领域:
化学工程
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可再生能源
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催化
·
可持续燃料
✓ 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）