scholarly journals Study on the Development of High-Performance P-Mo-V Catalyst and the Influence of Aldehyde Impurities on Catalytic Performance in Selective Oxidation of Methacrolein to Methacrylic Acid

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 394
Author(s):  
Baohe Wang ◽  
Honggang Dong ◽  
Liang Lu ◽  
Hongxia Liu ◽  
Zhaobang Zhang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Selective Oxidation ◽  
Methacrylic Acid ◽  
Structural Damage ◽  
High Performance ◽  
Competitive Adsorption ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Active Species ◽  
Catalyst Poisoning

A series of KxH1.1-xCu0.2Cs1(NH4)1.5PVMo11O40 (KxCuCsNH4PVA) catalysts with different x values were synthesized to catalyze the selective oxidation of methacrolein (MAL) to methacrylic acid (MAA). The effects of potassium (K) ions on both the structure and catalytic activity were studied in detail. The optimum K0.6CuCsNH4PVA exhibited a large surface area, more acid sites, and abundant active species (V4+/VO2+) in the secondary structure of the Keggin structure, consequently offering good catalytic performance. Furthermore, K ions increased the MAA selectivity at the expense of carbon monoxide and carbon dioxide (together defined as COX). Additionally, several process parameters for MAL oxidation were evaluated in the processing experiments. The effects of aldehyde impurities (formaldehyde and propanal) on the catalytic performance were investigated. Possible detrimental effects (catalyst poisoning and structural damage) of aldehyde impurities were excluded. A light decrease in MAL conversion could be attributed to the competitive adsorption of aldehyde impurities and MAL on the catalyst. Hopefully, this work contributes to the design of stable and feasible catalysts for the industrial production of MAA.

Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide by Heteropolyacid/Metal Oxide Catalysts

2007 ◽  
Vol 119 ◽  
pp. 287-290 ◽  
Author(s):  
Kyung Won La ◽  
Min Hye Youn ◽  
Jin Suk Chung ◽  
Sung Hyeon Baeck ◽  
In Kyu Song
Keyword(s):  
Carbon Dioxide ◽  
Metal Oxide ◽  
Dimethyl Carbonate ◽  
Batch Reactor ◽  
Direct Synthesis ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Pure Ceo2 ◽  
Autoclave Reactor

CexTi1-xO2 and H3PW12O40/CexTi1-xO2 catalysts were prepared by sol-gel method, and they were applied to the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide in a batch reactor. The reaction was carried out in an autoclave reactor at 170oC and 5 MPa. It was found that CexTi1-xO2 exhibited a higher catalytic performance than pure CeO2 and TiO2. The catalytic performance of CexTi1-xO2 was the maximum when x=0.1. It was also revealed that H3PW12O40/CexTi1-xO2 catalysts showed a remarkably enhanced catalytic performance than the corresponding CexTi1-xO2 catalysts. The amount of DMC produced by 15 wt% H3PW12O40/ Ce0.1Ti0.9O2 catalyst was six times higher than that produced by Ce0.1Ti0.9O2 catalyst. It is concluded that both Brönsted acid sites provided by H3PW12O40 and base sites in CexTi1-xO2 played an important role in improving the catalytic performance of H3PW12O40/CexTi1-xO2.

scholarly journals High-Performance Vapor-Phase Selective Oxidation of Ethyl Lactate to Ethyl Pyruvate over SiO2 Supported PMoVNb Oxides

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 197
Author(s):  
Xiaoyu Liu ◽  
Qi Wang ◽  
Chenghao Liu ◽  
Xiaolong Wang ◽  
Cuina Peng ◽  
...  
Keyword(s):  
Selective Oxidation ◽  
High Performance ◽  
High Selectivity ◽  
Mixed Oxides ◽  
Ethyl Pyruvate ◽  
Maximum Yield ◽  
Active Species ◽  
Ethyl Lactate ◽  
Superior Performance ◽  
Decarboxylation Reaction

This paper describes the application of P-Mo-V-Nb/SiO2 catalysts for the selective oxidation of ethyl lactate (EL) to ethyl pyruvate (EP). The P-Mo-V-Nb/SiO2 catalysts exhibit superior performance for EP selectivity than the corresponding samples of binary V-Nb/SiO2 ternary P-Mo-V/SiO2 and P-Mo-Nb/SiO2 catalysts at same temperatures. The origin of high EP selectivity of the P-Mo-V-Nb/SiO2 catalysts is explored and attributed to the synergistic effect of P, Mo, V, and Nb mixed oxides presented on the surface of the catalyst. The highly dispersive sites separated active species under the action of phosphorus, suppressing over oxidation and improving the selectivity. The existence of MoO3 to provide higher oxidation for catalyst. The redox cycle of V and Nb oxides could be completed through electron transfer between lattice oxygen and metal cations. Moreover, the weak acidity of catalyst surface is favorable to avoid the decarboxylation reaction to target a high selectivity of EP. Therefore, the P-Mo-V-Nb/SiO2 catalyst obtained the maximum yield of 91.8% with a selectivity of 93.8% and a conversion of 99.0% simultaneously at 280 °C.

scholarly journals Ni0.5Cu0.5Co2O4 Nanocomposites, Morphology, Controlled Synthesis, and Catalytic Performance in the Hydrolysis of Ammonia Borane for Hydrogen Production

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1334 ◽  
Author(s):  
Yufa Feng ◽  
Jin Zhang ◽  
Huilong Ye ◽  
Liling Li ◽  
Huize Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Ammonia Borane ◽  
Catalytic Performance ◽  
Active Species ◽  
High Catalytic Activity ◽  
Practical Applications ◽  
Production Of Hydrogen ◽  
Strong Candidate ◽  
Hydrolysis Of

The catalytic hydrolysis of ammonia borane (AB) is a promising route to produce hydrogen for mobile hydrogen‒oxygen fuel cells. In this study, we have successfully synthesized a variety of Ni0.5Cu0.5Co2O4 nanocomposites with different morphology, including nanoplatelets, nanoparticles, and urchin-like microspheres. The catalytic performance of those Ni0.5Cu0.5Co2O4 composites in AB hydrolysis is investigated. The Ni0.5Cu0.5Co2O4 nanoplatelets show the best catalytic performance despite having the smallest specific surface area, with a turnover frequency (TOF) of 80.2 molhydrogen·min−1·mol−1cat. The results reveal that, in contrast to the Ni0.5Cu0.5Co2O4 nanoparticles and microspheres, the Ni0.5Cu0.5Co2O4 nanoplatelets are more readily reduced, leading to the fast formation of active species for AB hydrolysis. These findings provide some insight into the design of high-performance oxide-based catalysts for AB hydrolysis. Considering their low cost and high catalytic activity, Ni0.5Cu0.5Co2O4 nanoplatelets are a strong candidate catalyst for the production of hydrogen through AB hydrolysis in practical applications.

scholarly journals Selective oxidation of methacrolein to methacrylic acid over H4PMo11VO40/C3N4-SBA-15

RSC Advances ◽  
2019 ◽  
Vol 9 (58) ◽  
pp. 34065-34075 ◽  
Author(s):  
Lilong Zhou ◽  
Shanshan Zhang ◽  
Zhengjie Li ◽  
Jason Scott ◽  
Zhikun Zhang ◽  
...  
Keyword(s):  
Selective Oxidation ◽  
Methacrylic Acid ◽  
Molecular Sieve ◽  
Carbon Nitride ◽  
Catalytic Performance

Molybdovanadylphosphoric acid (HPMV) was supported on a carbon nitride-modified SBA-15 (CN-SBA-15) molecular sieve to enhance its catalytic performance for oxidation of methacrolein (MAL) to methacrylic acid (MAA).

PEG400 Modification of Keggin-Type H4PMo11VO40-Based Catalysts for the Selective Oxidation of Methacrolein to Methacrylic Acid

2012 ◽  
Vol 550-553 ◽  
pp. 252-256 ◽  
Author(s):  
Li Yang ◽  
Heng Zhang ◽  
Rui Yi Yan ◽  
Xiang Ping Zhang ◽  
Guang Jin Zhang ◽  
...  
Keyword(s):  
Selective Oxidation ◽  
Methacrylic Acid ◽  
Phosphomolybdic Acid ◽  
Catalytic Performance ◽  
Optimum Conditions ◽  
Heteropoly Anion ◽  
Keggin Type ◽  
Surface Areas ◽  
Ft Ir ◽  
Specific Surface Areas

Keggin-type 12-phosphomolybdic acid with molybdenum partially substituted by vanadium and protons partially substituted by alkali and transition metals was synthesized for the selective oxidation of methacrolein to methacrylic acid. The structures of the catalysts were studied by FT-IR, XRD, TG-DTA and BET. The effects of the additive amount of PEG400, calcination temperature and the content of Cs on the catalytic performance were investigated. Results show that specific surface areas of the catalysts increase with the increase of PEG400 amount; PEG400 is removed at 250 °C and the primary structure of the catalysts is not changed with the addition of PEG400. The conversion and selectivity increase with the Cs content, and then decrease. The catalyst with the ratio of Cs+: heteropoly anion=1:1 exhibits good catalytic performance for the selective oxidation of MAL. Under the optimum conditions, the conversion of MAL and selectivity of MAA are 76.4% and 83.6% respectively.

scholarly journals Efficient Electrocatalytic Upgrading of Furan-Based Biomass: Key Roles of Two-Dimensional Mesoporous Heterostructure and Ternary Electrolyte

2021 ◽  
Author(s):  
Haoran Wu ◽  
Yashi Zou ◽  
Haishan Xu ◽  
Jianming Yang ◽  
Qinye Bao ◽  
...  
Keyword(s):  
High Performance ◽  
Biomass Conversion ◽  
Value Added ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Active Species ◽  
Heterocyclic Carbenes ◽  
Two Dimensional ◽  
Mechanism Study ◽  
Efficient Conversion

Abstract Development of high-performance electrocatalytic systems for efficient conversion of biomass to value-added chemicals under mild conditions and understanding of their mechanisms are of profound significance, but have remained a great challenge. Here, we report the first development of two-dimensional mesoporous electrocatalyst for biomass conversion. The electrocatalyst (meso-PA/PmPD/GO) consists of phytic acid (PA)-doped mesoporous poly(m-phenylenediamine) layers coated on graphene oxide nanosheets. Meanwhile, a high-performance ternary electrolyte containing 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4), acetonitrile and H2O is developed. The combination of meso-PA/PmPD/GO and the ternary electrolyte realizes highly efficient conversion of two important biomass derivatives at room temperature. One involves a hardly achieved oxidation of furfuryl alcohol to 6-hydroxy-2,3-dihydro-6H-pyrano-3-one with high faradic efficiency (FE: 83.7%) and selectivity (87.9%). The other involves the oxidation of furfural to 5-hydroxy-2(5H)-furanone with record-high FE (98.9%) and selectivity (93.6%). Mechanism study including DFT calculations unveils that N-heterocyclic carbenes (Bmim*) generated from BmimBF4 act as the reaction-determining active species. Additionally, the synergistic effect of the PA doping, mesoporous structure and p-n heterojunction interface in meso-PA/PmPD/GO favors the mass transport and the transfer of generated holes to the outer layers, thus boosting the catalytic performance.

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