Defective Nb2O5-supported Pt catalysts for CO oxidation: Promoting catalytic activity via oxygen vacancy engineering

Tran, Si Bui Trung; Choi, Hye Duck; Oh, Sang‐Hun; Park, Jeong Young

doi:10.1016/j.jcat.2019.05.017

Cited by 76 publications

(32 citation statements)

References 69 publications

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“…The availability of surface oxygen vacancies is observed as the supreme reactive sites in catalysis. These oxygen vacancies are found to stimulate the disintegration of water molecules into active OH radicals, providing the opportunity to develop a vigorous catalyst in the presence of water vapor [57][58][59][60]. The higher selectivity for benzaldehyde can be explained due to the presence of an oxygen vacancy cluster, which leads to a faster oxidation rate and doesn't allow further dissociation of the desired product.…”

Section: Influence Of Cerium Content On Catalytic Activitymentioning

confidence: 99%

Nanocrystalline cerium-doped Y-type barium hexaferrite; a useful catalyst for selective oxidation of styrene

Suthar

Srivastava

Joshi

et al. 2020

J Mater Sci: Mater Electron

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The cerium-doped Y-type barium hexaferrites Ba 2−x Ce x Co 2 Fe 12 O 22 (x = 0.0, 0.1, 0.2, and 0.3) were synthesized using the sol-gel auto combustion method. The synthesized nanocrystalline hexaferrite powders were characterized; especially it's structural, morphological, and magnetic properties, through X-ray diffractometer, FTIR spectroscopy, scanning electron microscopy and vibrating sample magnetometer, respectively. The effects of catalyst amount, reaction temperature and time, solvent and oxidizing agent required for the entire conversion of styrene to benzaldehyde were also examined with pure Y-type barium hexaferrite (BrM). The catalytic performance of the BrM powder was measured for its suitability in the oxidation of styrene using various oxidants, and the isolated yield of the benzaldehyde was calculated using the column chromatography separation. The as-prepared 20 mg BrM samples showed total conversion of styrene and 66% isolated yield for benzaldehyde at 120 °C for 24 h in the presence of trifluoroacetic acid as an oxidant. The effect of cerium doping on the benzaldehyde selectivity was also analyzed at optimized conditions and found that cerium-doped samples showed excellent catalytic performance. Paralleled with the pristine barium hexaferrite, the catalytic efficiency was significantly enriched and exhibited its maximum performance with Ba 1.8 Ce 0.2 Co 2 Fe 12 O 22 ferrite, almost 71% selectivity was achieved with the same reaction conditions. This enhanced performance was correlated with the XPS studies for x = 0.2 sample. The as-prepared catalyst was magnetically separable to reprocess. There was no remarkable loss of catalytic activity when it was reprocessed for five consecutive trials.

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Section: Influence Of Cerium Content On Catalytic Activitymentioning

confidence: 99%

Nanocrystalline cerium-doped Y-type barium hexaferrite; a useful catalyst for selective oxidation of styrene

Suthar

Srivastava

Joshi

et al. 2020

J Mater Sci: Mater Electron

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“…The trap state distribution and low interfacial barrier of T-Nb 2 O 5 can help to reduce the reverse electron transfer rate and lower injection yield on the nanosecond time scale in comparison with the traditional catalyst of anatase TiO 2 . [21,22] To enhance the specific surface areas (SSAs) of the Nb 2 O 5 nanofibers (NFs), we developed a polymer-template sol−gel electrospinning method to create ordered mesopores throughout the NFs. It is worthy to note that the mesoporous Nb 2 O 5 NF film was white and flexible.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Flexible Mesoporous Black Nb₂O₅ Nanofiber Films for Visible‐Light‐Driven Photocatalytic CO₂ Reduction into CH₄

et al. 2022

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Achieving high selectivity and conversion efficiency simultaneously is a challenge for visible-light-driven photocatalytic CO 2 reduction into CH 4 . Here, a facile nanofiber synthesis method and a new defect control strategy at room-temperature are reported for the fabrication of flexible mesoporous black Nb 2 O 5 nanofiber catalysts that contain abundant oxygen-vacancies and unsaturated Nb dual-sites, which are efficient towards photocatalytic production of CH 4 . The oxygen-vacancy decreases the bandgap width of Nb 2 O 5 from 3.01-2.25 eV, which broadens the light-absorption range from ultraviolet to visible-light, and the dual sites in the mesopores can easily adsorb CO 2 , so that the intermediate product of CO* can be spontaneously changed into *CHO. The formation of a highly stable NbCHO* intermediate at the dual sites is proposed to be the key feature determining selectivity. The preliminary results show that without using sacrificial agents and photosensitizers, the nanofiber catalyst achieves 64.8% selectivity for CH 4 production with a high evolution rate of 19.5 µmol g −1 h −1 under visible-light. Furthermore, the flexible catalyst film can be directly used in devices, showing appealing and broadly commercial applications.

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“…García-Sancho, Agirrezabal-Telleria, et al, 2014;C. García-Sancho, Rubio-Caballero, et al, 2014;Molina et al, 2015;Tirsoaga et al, 2021), hydrolysis (Campisi et al, 2018;Carniti et al, 2016;Catrinck et al, 2020;Maciel et al, 2020;Nogueira et al, 2020), oxidation (Cecchi et al, 2018;Chagas et al, 2013;Ding et al, 2020;Oliveira et al, 2012;Tran et al, 2019;Wasalathanthri et al, 2019;Wolski, 2020), esterification and transesterification (Câmara & Aranda, 2011;Deshmane et al, 2010;Cristina García-Sancho et al, 2011;Gonçalves et al, 2011;Hoekman et al, 2012;Miranda et al, 2011;Rezende et al, 2019;Singh et al, 2019), isomerization (Carniti et al, 2016;Kitano et al, 2012;Nogueira et al, 2020;Scaldaferri & Pasa, 2019a, 2019bWei et al, 2019), and photocatalytic reactions (Costa et al, 2020;Hashemzadeh et al, 2014;Moraes et al, 2020;Raba-Paéz et al, 2020). In the literature, the niobium compounds most used as catalysts are niobium pentoxide, niobic acid, and niobium phosphate.…”

Section: Niobium Compounds Catalysts and Their Propertiesmentioning

confidence: 99%

Uso de compostos de nióbio como catalisadores na produção de biocombustíveis: uma revisão

Moreira¹,

Souza²,

Silva³

et al. 2022

J. Eng. Exact Sci.

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A necessidade de substituir combustíveis fósseis por biocombustíveis não é um tema recente na comunidade acadêmica. Pesquisadores estudam e desenvolvem combustíveis alternativos há décadas e, com isso, combustíveis como o biodiesel e o etanol de primeira geração se consolidaram no mercado. No entanto, esses biocombustíveis de primeira geração competem com a indústria de alimentos, o que afeta sua oferta e preço. Por outro lado, os combustíveis de segunda geração são produzidos a partir de biomassa lignocelulósica e resíduos orgânicos de atividades urbanas e agroindustriais, não competindo com a indústria de alimentos. No entanto, a maioria desses processos ainda não é economicamente viável. Duas das principais contribuições para essa inviabilidade são o baixo desempenho dos processos (baixa conversão da matéria-prima e baixa seletividade dos produtos de interesse) e o alto custo dos catalisadores, que muitas vezes são feitos de metais nobres de pouca disponibilidade. O Nióbio é um metal com diversas aplicações, mas ainda pouco explorado industrialmente como catalisador, apesar de possuir propriedades interessantes para essa finalidade. Este artigo de revisão compila trabalhos envolvendo o uso do nióbio e seus compostos como catalisador em diversos processos de produção de biocombustíveis, como esterificação, pirólise, liquefação, síntese Fischer-Tropsch, desoxigenação, entre outros. Além da revisão da literatura, este artigo apresenta uma análise crítica a respeito das aplicações de cada processo e tecnologia, bem como das pesquisas desenvolvidas pelos autores.

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Defective Nb2O5-supported Pt catalysts for CO oxidation: Promoting catalytic activity via oxygen vacancy engineering

Cited by 76 publications

References 69 publications

Nanocrystalline cerium-doped Y-type barium hexaferrite; a useful catalyst for selective oxidation of styrene

Nanocrystalline cerium-doped Y-type barium hexaferrite; a useful catalyst for selective oxidation of styrene

Fabrication of Flexible Mesoporous Black Nb₂O₅ Nanofiber Films for Visible‐Light‐Driven Photocatalytic CO₂ Reduction into CH₄

Uso de compostos de nióbio como catalisadores na produção de biocombustíveis: uma revisão

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Defective Nb2O5-supported Pt catalysts for CO oxidation: Promoting catalytic activity via oxygen vacancy engineering

Cited by 76 publications

References 69 publications

Nanocrystalline cerium-doped Y-type barium hexaferrite; a useful catalyst for selective oxidation of styrene

Nanocrystalline cerium-doped Y-type barium hexaferrite; a useful catalyst for selective oxidation of styrene

Fabrication of Flexible Mesoporous Black Nb2O5 Nanofiber Films for Visible‐Light‐Driven Photocatalytic CO2 Reduction into CH4

Uso de compostos de nióbio como catalisadores na produção de biocombustíveis: uma revisão

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Fabrication of Flexible Mesoporous Black Nb₂O₅ Nanofiber Films for Visible‐Light‐Driven Photocatalytic CO₂ Reduction into CH₄