Promotion of the Selective Hydrogenation of Unsaturated Aldehydes with Pt-Cu Bimetallics: From Surface Science to Nanostructured Catalysts

用 Pt-Cu 双金属促进不饱和醛的选择性加氢：从表面科学到纳米结构催化剂

• 批准号: 1660433
• 负责人: Francisco Zaera
• 金额: $ 45万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1660433&HistoricalAwards=false
• 关键词: Promotion; Selective; Hydrogenation; Unsaturated; Aldehydes

Heterogeneous catalysis is used in many industrial chemical processes to make the chemical reactions occur through more selective and efficient chemical pathways, and the design of the solid material heterogeneous catalysts that help to effect these chemical transformations is a field of intensive study. Dr. Francisco Zaera of the University of California-Riverside is investigating the properties of Cu-Pt alloys to determine the effect of adding copper to very active but not particularly selective platinum catalysts with the aim of improving their selectivity to produce desired products while limiting the creation of unwanted byproducts. Dr. Zaera's goal is to design a catalyst that can bring about the reaction of carbon-oxygen (C=O) bonds to alcohols, without affecting other bonds in the molecule. He performs a three-pronged approach to understand the mechanisms in these reactions; kinetic measurements on model systems with few, well-defined surface sites that probe the surface-layer composition and reactivity of the Cu-Pt materials under well-defined, low-pressure conditions; reactions performed on model catalysts and reactions under actual catalytic conditions and; studies with well-defined, supported catalysts that most closely resemble industrial catalysts in their structure and complexity. Broader impacts of this work result from an enhanced fundamental understanding of the molecule-level chemistry of mixed-metal surfaces. The knowledge deriving from this work has broader impact in education as well, by providing data to illustrate basic principles in kinetics and catalysis for undergraduate and graduate classes. The PI is also active in promoting collaborations with Latin American research groups and recruits students from groups underrepresented in STEM fields, Hispanics in particular, to participate in research activities.Dr. Francisco Zaera of the University of California-Riverside is supported by the Chemical Catalysis Program to investigate the catalytic properties of Cu-Pt alloys in the selective hydrogenation of C=O bonds. One of the major challenges in catalysis is to achieve high selectivity toward the desired products. It has been shown that selectivity may be controlled by mixing two or more metals, an approach that is used in many industrial applications but not fully understood. The focus of this proposal is to help resolve some pending issues associated with bimetallic catalysis, including the determination of the contributions of electronic versus geometrical effects and the identification of the most active surface in terms of the degree of metal intermixing and the oxidation states of the constituent elements. Dr. Zaera combines fundamental surface-science studies on the mechanistic details of the reactions with the design and evaluation of realistic catalysts. . Three types of interconnected experiments are involved : (1) kinetic measurements on model systems using high-flux molecular beams to emulate close-to-atmospheric pressures locally at specific surfaces while maintaining the ultrahigh vacuum (UHV) environment necessary for their controlled preparation and characterization; (2) research of model systems in operando mode by combining kinetic measurements with mass spectrometry detection and characterization of the surface intermediates using infrared absorption spectroscopy; and (3) kinetic measurements with well-defined supported catalysts made by using colloidal and other nanotechnologies. Broader impacts of the research result for an improved understanding of catalytic selectivity, which translates into more efficient hydrogenation catalysts particularly important to the industrial production of fine chemicals. Broader impacts are also made in curriculum development by providing data to illustrate basic principles in kinetics, catalysis, and nanoparticle synthesis for undergraduate and graduate classes. The PI is also active in forging collaborations with Latin American research groups, and in the recruitment of students from groups underrepresented in STEM research fields, with a particular focus on Hispanics.

多相催化被应用于许多工业化学过程中，以使化学反应通过更选择性和更有效的化学途径发生，而有助于实现这些化学转化的固体材料多相催化剂的设计是一个深入研究的领域。加州大学河滨分校的Francisco Zaera博士正在研究铜-铂合金的性质，以确定在非常活性但选择性不是特别高的铂催化剂中添加铜的效果，目的是提高它们生产所需产品的选择性，同时限制不需要的副产品的产生。Zaera博士的目标是设计一种催化剂，可以在不影响分子中其他键的情况下，实现碳-氧(C=O)键与醇的反应。他采用三管齐下的方法来了解这些反应中的机理；对具有少数明确定义的表面位置的模型系统进行动力学测量，以探索明确定义的低压条件下铜-铂材料的表面层组成和反应性；在模型催化剂上进行的反应和在实际催化条件下进行的反应；以及对定义明确的负载型催化剂进行的研究，这些催化剂在结构和复杂性上与工业催化剂非常相似。这项工作的更广泛的影响来自于对混合金属表面分子水平化学的基础理解的增强。从这项工作中获得的知识也在教育中产生了更广泛的影响，通过为本科生和研究生提供数据来说明动力学和催化的基本原理。国际和平研究所还积极促进与拉丁美洲研究小组的合作，并从STEM领域代表性不足的群体，特别是拉美裔美国人中招募学生参加研究活动。加州大学河滨分校的Francisco Zaera在化学催化计划的支持下，研究了铜-铂合金在C=O键选择加氢中的催化性能。催化领域的主要挑战之一是实现对所需产品的高选择性。已经证明，选择性可以通过混合两种或两种以上的金属来控制，这种方法在许多工业应用中都有使用，但还没有完全被理解。这项提案的重点是帮助解决与双金属催化有关的一些悬而未决的问题，包括确定电子效应对几何效应的贡献，以及根据金属混合程度和组成元素的氧化态确定最活跃的表面。扎埃拉博士将对反应机理细节的基础表面科学研究与现实催化剂的设计和评估结合起来。。三类相互关联的实验涉及：(1)使用高通量分子束对模型体系进行动力学测量，以模拟特定表面的局部接近大气压的压力，同时保持受控制备和表征所需的超高真空(UHV)环境；(2)通过将动力学测量与质谱学检测相结合，以操作式模式研究模型体系，并使用红外吸收光谱对表面中间体进行表征；以及(3)利用胶体和其他纳米技术对定义明确的负载型催化剂进行动力学测量。研究结果对更好地理解催化选择性产生了更广泛的影响，这转化为更有效的加氢催化剂，对精细化学品的工业生产特别重要。通过为本科生和研究生课程提供数据来说明动力学、催化和纳米粒子合成的基本原理，课程开发也产生了更广泛的影响。国际和平研究所还积极与拉丁美洲研究小组建立合作关系，并从STEM研究领域代表性不足的群体中招收学生，特别关注拉美裔美国人。

项目成果

Switch in Relative Stability between cis and trans 2-Butene on Pt(111) as a Function of Experimental Conditions: A Density Functional Theory Study

• DOI: 10.1021/acscatal.8b00544
• 发表时间: 2018-03
• 期刊: ACS Catalysis
• 影响因子: 12.9
• 作者: Jinyu Li;P. Fleurat‐Lessard;F. Zaera;F. Delbecq

Atomic Layer Deposition (ALD) as a Way to Prepare New Mixed-Oxide Catalyst Supports: The Case of Alumina Addition to Silica-Supported Platinum for the Selective Hydrogenation of Cinnamaldehyde

• DOI: 10.1007/s11244-019-01163-4
• 发表时间: 2019-09
• 期刊: Topics in Catalysis
• 影响因子: 3.6
• 作者: Zhihuan Weng;F. Zaera

Synthesis of Chiral Dendrimer-Encapsulated Nanoparticle (DEN) Catalysts

• DOI: 10.1007/s11244-018-0955-9
• 发表时间: 2018-05
• 期刊: Topics in Catalysis
• 影响因子: 3.6
• 作者: Zhihuan Weng;F. Zaera

Controlling Selectivity in Unsaturated Aldehyde Hydrogenation Using Single-Site Alloy Catalysts

• DOI: 10.1021/acscatal.9b02547
• 发表时间: 2019-10-01
• 期刊: ACS CATALYSIS
• 影响因子: 12.9
• 作者: Cao, Yueqiang;Chen, Bo;Zaera, Francisco
• 通讯作者: Zaera, Francisco