Optimization of a Hierarchical Porous-Structured Reactor to Mitigate Mass Transport Limitations for Efficient Electrocatalytic Ammonia Oxidation through a Three-Electron-Transfer Pathway

2021 ◽  
Author(s):  
Zichen Liu ◽  
Gong Zhang ◽  
Huachun Lan ◽  
Huijuan Liu ◽  
Jiuhui Qu
Keyword(s):  
Electron Transfer ◽  
Mass Transport ◽  
Ammonia Oxidation ◽  
Electron Transfer Pathway ◽  
Hierarchical Porous ◽  
Structured Reactor

scholarly journals A Hybrid Extracellular Electron Transfer Pathway Enhances the Survival of Vibrio natriegens

2020 ◽  
Vol 86 (19) ◽  
Author(s):  
Bridget E. Conley ◽  
Matthew T. Weinstock ◽  
Daniel R. Bond ◽  
Jeffrey A. Gralnick
Keyword(s):  
Electron Transfer ◽  
Shewanella Oneidensis ◽  
Anaerobic Respiration ◽  
Basic Research ◽  
Extracellular Electron Transfer ◽  
Content Type ◽  
Electron Transfer Pathway ◽  
Sedimentary Environments ◽  
Genetic Potential ◽  
Iron And Manganese

ABSTRACT Vibrio natriegens is the fastest-growing microorganism discovered to date, making it a useful model for biotechnology and basic research. While it is recognized for its rapid aerobic metabolism, less is known about anaerobic adaptations in V. natriegens or how the organism survives when oxygen is limited. Here, we describe and characterize extracellular electron transfer (EET) in V. natriegens, a metabolism that requires movement of electrons across protective cellular barriers to reach the extracellular space. V. natriegens performs extracellular electron transfer under fermentative conditions with gluconate, glucosamine, and pyruvate. We characterized a pathway in V. natriegens that requires CymA, PdsA, and MtrCAB for Fe(III) citrate and Fe(III) oxide reduction, which represents a hybrid of strategies previously discovered in Shewanella and Aeromonas. Expression of these V. natriegens genes functionally complemented Shewanella oneidensis mutants. Phylogenetic analysis of the inner membrane quinol dehydrogenases CymA and NapC in gammaproteobacteria suggests that CymA from Shewanella diverged from Vibrionaceae CymA and NapC. Analysis of sequenced Vibrionaceae revealed that the genetic potential to perform EET is conserved in some members of the Harveyi and Vulnificus clades but is more variable in other clades. We provide evidence that EET enhances anaerobic survival of V. natriegens, which may be the primary physiological function for EET in Vibrionaceae. IMPORTANCE Bacteria from the genus Vibrio occupy a variety of marine and brackish niches with fluctuating nutrient and energy sources. When oxygen is limited, fermentation or alternative respiration pathways must be used to conserve energy. In sedimentary environments, insoluble oxide minerals (primarily iron and manganese) are able to serve as electron acceptors for anaerobic respiration by microorganisms capable of extracellular electron transfer, a metabolism that enables the use of these insoluble substrates. Here, we identify the mechanism for extracellular electron transfer in Vibrio natriegens, which uses a combination of strategies previously identified in Shewanella and Aeromonas. We show that extracellular electron transfer enhanced survival of V. natriegens under fermentative conditions, which may be a generalized strategy among Vibrio spp. predicted to have this metabolism.

Surface polaron states on single-crystal rutile TiO2 nanorod arrays enhancing charge separation and transfer

2020 ◽  
Vol 49 (42) ◽  
pp. 15054-15060
Author(s):  
Qimeng Yang ◽  
Heng Zhu ◽  
Yanghui Hou ◽  
Duanduan Liu ◽  
Huang Tang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Single Crystal ◽  
Charge Separation ◽  
Nanorod Arrays ◽  
Rutile Tio2 ◽  
Electron Transfer Pathway ◽  
Tio2 Nanorod ◽  
Electrolyte Interface ◽  
Tio2 Nanorod Arrays

Polaron states on single-crystal TiO2 photoanodes provide an important electron transfer pathway at the electrode–electrolyte interface.

N-doped hierarchical porous metal-free catalysts derived from covalent triazine frameworks for the efficient oxygen reduction reaction

2019 ◽  
Vol 9 (23) ◽  
pp. 6606-6612 ◽  
Author(s):  
Yaqi Cao ◽  
Yuanzhi Zhu ◽  
Xifan Chen ◽  
Bahreselam Sielu Abraha ◽  
Wenchao Peng ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Oxygen Reduction Reaction ◽  
Oxygen Diffusion ◽  
Active Sites ◽  
Porous Metal ◽  
Reduction Reaction ◽  
Metal Free ◽  
Hierarchical Porous ◽  
The Hierarchical Structure ◽  
Catalytic Active Sites

The hierarchical structure enhances oxygen diffusion, improves electron transfer, and exposes more catalytic active sites for the ORR.

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