Calorimetric and spectroscopic studies on solvation energetics for H2storage in the CO2/HCOOH system

2016 ◽  
Vol 18 (16) ◽  
pp. 10764-10773 ◽  
Author(s):  
Cornel Fink ◽  
Sergey Katsyuba ◽  
Gabor Laurenczy
Keyword(s):  
Carbon Dioxide ◽  
Formic Acid ◽  
Spectroscopic Studies ◽  
Solvent Interactions ◽  
System P ◽  
Role Of Solvent

The role of solvent interactions in H2-storage/delivery in the carbon dioxide–formic acid couple.

scholarly journals On the Mechanism of Carbon Dioxide Reduction on Sn-Based Electrodes: Insights into the Role of Oxide Surfaces

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 636 ◽  
Author(s):  
Giane B. Damas ◽  
Caetano R. Miranda ◽  
Ricardo Sgarbi ◽  
James M. Portela ◽  
Mariana R. Camilo ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Electron Transfer ◽  
Formic Acid ◽  
Oxide Layer ◽  
Co2 Reduction ◽  
Carbon Dioxide Reduction ◽  
Oxide Surfaces ◽  
In Situ Conditions

The electrochemical reduction of carbon dioxide into carbon monoxide, hydrocarbons and formic acid has offered an interesting alternative for a sustainable energy scenario. In this context, Sn-based electrodes have attracted a great deal of attention because they present low price and toxicity, as well as high faradaic efficiency (FE) for formic acid (or formate) production at relatively low overpotentials. In this work, we investigate the role of tin oxide surfaces on Sn-based electrodes for carbon dioxide reduction into formate by means of experimental and theoretical methods. Cyclic voltammetry measurements of Sn-based electrodes, with different initial degree of oxidation, result in similar onset potentials for the CO2 reduction to formate, ca. −0.8 to −0.9 V vs. reversible hydrogen electrode (RHE), with faradaic efficiencies of about 90–92% at −1.25 V (vs. RHE). These results indicate that under in-situ conditions, the electrode surfaces might converge to very similar structures, with partially reduced or metastable Sn oxides, which serve as active sites for the CO2 reduction. The high faradaic efficiencies of the Sn electrodes brought by the etching/air exposition procedure is ascribed to the formation of a Sn oxide layer with optimized thickness, which is persistent under in situ conditions. Such oxide layer enables the CO2 “activation”, also favoring the electron transfer during the CO2 reduction reaction due to its better electric conductivity. In order to elucidate the reaction mechanism, we have performed density functional theory calculations on different slab models starting from the bulk SnO and Sn6O4(OH)4 compounds with focus on the formation of -OH groups at the water-oxide interface. We have found that the insertion of CO2 into the Sn-OH bond is thermodynamically favorable, leading to the stabilization of the tin-carbonate species, which is subsequently reduced to produce formic acid through a proton-coupled electron transfer process. The calculated potential for CO2 reduction (E = −1.09 V vs. RHE) displays good agreement with the experimental findings and, therefore, support the CO2 insertion onto Sn-oxide as a plausible mechanism for the CO2 reduction in the potential domain where metastable oxides are still present on the Sn surface. These results not only rationalize a number of literature divergent reports but also provide a guideline for the design of efficient CO2 reduction electrocatalysts.

The Role of Solvent Interactions in Protein Conformatio

1975 ◽  
Vol 3 (2) ◽  
pp. 165-219 ◽  
Author(s):  
F. Franks ◽  
D. Eagland ◽  
R. Lumry
Keyword(s):  
Solvent Interactions ◽  
Role Of Solvent

Photochemical and Electrochemical Reduction of Carbon Dioxide Catalyzed by a Polyoxometalate-Organic Photosensitizer Complex

2018 ◽  
Author(s):  
Chandan Dey ◽  
Ronny Neumann
Keyword(s):  
Carbon Dioxide ◽  
Cyclic Voltammetry ◽  
Formic Acid ◽  
Electrochemical Reduction ◽  
Mass Spectroscopy ◽  
Photochemical Reactions ◽  
Reducing Agent ◽  
Covalent Attachment ◽  
Hybrid Complex ◽  
Open Face

<p>A manganese substituted Anderson type polyoxometalate, [MnMo<sub>6</sub>O<sub>24</sub>]<sup>9-</sup>, tethered with an anthracene photosensitizer was prepared and used as catalyst for CO<sub>2</sub> reduction. The polyoxometalate-photosensitizer hybrid complex, obtained by covalent attachment of the sensitizer to only one face of the planar polyoxometalate, was characterized by NMR, IR and mass spectroscopy. Cyclic voltammetry measurements show a catalytic response for the reduction of carbon dioxide, thereby suggesting catalysis at the manganese site on the open face of the polyoxometalate. Controlled potentiometric electrolysis showed the reduction of CO<sub>2</sub> to CO with a TOF of ~15 sec<sup>-1</sup>. Further photochemical reactions showed that the polyoxometalate-anthracene hybrid complex was active for the reduction of CO<sub>2</sub> to yield formic acid and/or CO in varying amounts dependent on the reducing agent used. Control experiments showed that the attachment of the photosensitizer to [MnMo<sub>6</sub>O<sub>24</sub>]<sup>9-</sup> is necessary for photocatalysis.</p><div><br></div>

Introduction

2018 ◽  
Author(s):  
Francis L. F Lee ◽  
Joseph M Chan
Keyword(s):  
Hong Kong ◽  
Social Movement ◽  
Media System ◽  
System P ◽  
Connective Action ◽  
Integrated Media ◽  
Media And Communication ◽  
The Ideal

Chapter 1 introduces the background of the Umbrella Movement, a protest movement that took hold in Hong Kong in 2014, and outlines the theoretical principles underlying the analysis of the role of media and communication in the occupation campaign. It explicates how the Umbrella Movement is similar to but also different from the ideal-typical networked social movement and crowd-enabled connective action. It explains why the Umbrella Movement should be seen as a case in which the logic of connective action intervenes into a planned collective action. It also introduces the notion of conditioned contingencies and the conceptualization of an integrated media system.

Choice Matters

2018 ◽  
Author(s):  
Gordon Moore ◽  
John A. Quelch ◽  
Emily Boudreau
Keyword(s):  
Public Policy ◽  
Social Media ◽  
Healthcare Provider ◽  
Healthcare System ◽  
Consumer Choice ◽  
Marketing Management ◽  
Appropriate Use ◽  
System P ◽  
The U.S

Choice Matters: How Healthcare Consumers Make Decisions (and Why Clinicians and Managers Should Care) is a timely and thoughtful exploration of the controversial role of consumers in the U.S. healthcare system. In most markets today, consumers have more options and autonomy than ever before. Empowered consumers easily shop around for products and services that better meet their needs, and they widely share their reviews on social media to inform and influence other consumers. Businesses have responded with better experiences and prices to compete for consumers’ business. Though healthcare has lagged behind other industries in this respect, there is a rising tide of interest in consumer choice and empowerment in healthcare markets. However, most healthcare provider organizations, individual doctors, and health insurers are unprepared to consider patients as consumers. The authors draw upon the fields of medicine, marketing, management, psychology, and public policy as they take a substantive, in-depth look at consumer choice and point out its appropriate use, as well as its limitations. This book addresses perplexing issues, such as how healthcare differs from other consumer-driven markets, how consumers make healthcare decisions, and how increased consumer choice in healthcare can not only aid and empower American consumers but also improve the overall healthcare system.

Beyond Bias

2020 ◽  
pp. 736-753
Author(s):  
Chelsea Barabas
Keyword(s):  
Best Practices ◽  
Criminal Law ◽  
Criminal Justice Reform ◽  
Trade Offs ◽  
System P ◽  
Accuracy Measures ◽  
Criminal Legal System ◽  
And Function ◽  
Role And Function

This chapter discusses contemporary debates regarding the use of artificial intelligence as a vehicle for criminal justice reform. It closely examines two general approaches to what has been widely branded as “algorithmic fairness” in criminal law: the development of formal fairness criteria and accuracy measures that illustrate the trade-offs of different algorithmic interventions; and the development of “best practices” and managerialist standards for maintaining a baseline of accuracy, transparency, and validity in these systems. Attempts to render AI-branded tools more accurate by addressing narrow notions of bias miss the deeper methodological and epistemological issues regarding the fairness of these tools. The key question is whether predictive tools reflect and reinforce punitive practices that drive disparate outcomes, and how data regimes interact with the penal ideology to naturalize these practices. The chapter then calls for a radically different understanding of the role and function of the carceral state, as a starting place for re-imagining the role of “AI” as a transformative force in the criminal legal system.

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