权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Catalytic Selectivity Control in Electrochemical Systems using Self-Assembled Monolayers

使用自组装单层膜控制电化学系统中的催化选择性

基本信息

批准号：
2004090
负责人：
Will Medlin
金额：
$ 69.82万
依托单位：
University of Colorado at Boulder
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-15 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2004090&HistoricalAwards=false
关键词：
Catalytic Selectivity Control Electrochemical Systems

项目摘要

A major limitation of many chemical processes for synthesis of fuels and chemicals is the formation of unwanted byproducts. Catalysts are often used to direct chemical reactions towards desirable products. Combining electrochemistry with catalysis (i.e., electrocatalysis) opens the door not only to improved process selectivity, but also to improved energy efficiency and reduced environmental impact via sustainable and/or renewable energy from power sources such as wind and solar energy, and biomass. The study investigates modifications to electrocatalyst composition by surface coatings known as organic self-assembled monolayers (SAMS). The SAMS can be used in conjunction with electrocatalysts to convert renewable materials such as biomass to higher-value fuels and chemicals. The project will include training of postdoctoral researchers, graduate students, and community college instructors and students. Faculty and students on the project will prepare online instructional materials on electrochemistry that will be broadly disseminated.This project will develop new tools for selectivity control that employ an applied voltage to manipulate the structure of the catalyst, and thus its catalytic properties. Although “passive” SAMs have been used previously to improve catalyst performance, here the focus will be on the use of “active” SAMs that change their structure in response to the electric charge on the surface. Catalysts will be modified with ligands that undergo reversible coupling reactions or form bonds to the surface as a result of changes in electric potential. Such SAM-modified catalysts will then be evaluated for reactions where selectivity is a major challenge, using applied voltage as a new control for enhancing performance. The project will advance knowledge of how the organic near-surface environment can be designed to control selectivity on electrocatalysts and identify methods to design switchable surfaces that can hypothetically turn particular catalyst functions “on” or “off” using an electrical signal. To develop catalysts with electrically responsive coatings, the project will focus on the deposition of organothiolate SAMs on late transition metal surfaces such as Pd, Pt, and Au, and on SAM structures that have been shown to undergo potential-dependent changes in oxidation state, shape, and/or chemical bonding. The objectives of the project are to (i) conduct initial investigations of the use of SAM-modified catalysts under electrochemical conditions for a reaction system that has been thoroughly investigated in thermal catalysis to identify how the electrochemical environment affects the SAM; (ii) develop new methods to control cross-linking and surface density in SAMs that will provide fundamental information on design rules for potential-responsive systems; and (iii) modify catalysts with electroactive SAMs that enable potential-driven switching of catalyst performance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

用于合成燃料和化学品的许多化学过程的主要限制是形成不需要的副产物。催化剂通常用于引导化学反应生成所需产物。将电化学与催化相结合（即，电催化）不仅为改进工艺选择性打开了大门，而且也为通过来自电源（例如风能和太阳能）和生物质的可持续和/或可再生能量来改进能量效率和减少环境影响打开了大门。该研究调查了被称为有机自组装单分子层（SAMS）的表面涂层对电催化剂组合物的修饰。 SAMS可与电催化剂结合使用，将生物质等可再生材料转化为更高价值的燃料和化学品。该项目将包括培训博士后研究人员、研究生和社区学院的教师和学生。参与该项目的教师和学生将编写广泛传播的电化学在线教学材料。该项目将开发选择性控制的新工具，该工具采用外加电压来操纵催化剂的结构，从而操纵其催化性能。虽然“被动”SAM以前已被用于改善催化剂性能，但这里的重点将是使用“主动”SAM，其响应于表面上的电荷而改变其结构。催化剂将被配体修饰，配体经历可逆偶联反应或由于电势的变化而与表面形成键。然后将使用施加的电压作为提高性能的新控制，对选择性是主要挑战的反应评估这种SAM改性的催化剂。该项目将增进关于如何设计有机近地表环境以控制电催化剂选择性的知识，并确定设计可切换表面的方法，这些表面可以假设使用电信号“打开”或“关闭”特定催化剂功能。为了开发具有电响应涂层的催化剂，该项目将专注于在后过渡金属表面（如Pd，Pt和Au）上沉积有机硫醇盐SAM，以及SAM结构，这些SAM结构已被证明在氧化态，形状和/或化学键合方面发生电位依赖性变化。该项目的目标是：（一）对在电化学条件下使用SAM改性催化剂的反应系统进行初步研究，该反应系统已在热催化方面得到彻底研究，以确定电化学环境如何影响SAM;（二）开发控制SAM中的交联和表面密度的新方法，这将为电位响应系统的设计规则提供基本信息;和（iii）用电活性SAM改性催化剂，使催化剂性能的潜在驱动转换成为可能。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Understanding Reactivity of Self-Assembled Monolayer-Coated Electrodes: SAM-Induced Surface Reconstruction

DOI：
10.1016/j.electacta.2023.142586
发表时间：
2023-05
期刊：
Electrochimica Acta
影响因子：
6.6
作者：
Francisco W. S. Lucas;Nathanael C. Ramos;D. K. Schwartz;J. Medlin;Adam Holewinski
通讯作者：
Francisco W. S. Lucas;Nathanael C. Ramos;D. K. Schwartz;J. Medlin;Adam Holewinski

Directing Reaction Pathways on Supported Metal Catalysts with Low-Density Self-Assembled Monolayers