Probing the Nature of the Single-Atom Sites in Single-Site Alloy (SAA) Catalysts

探究单位点合金 (SAA) 催化剂中单原子位点的性质

• 批准号: 1953843
• 负责人: Francisco Zaera
• 金额: $ 51万
• 依托单位: University of California-Riverside
• 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: 2020-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1953843&HistoricalAwards=false
• 关键词: Probing; Nature; Single; Atom; Sites

Solid catalysts - used to speed up chemical reactions - are very common in industry and used in approximately 80% of all chemical processes. Solid catalysts are applied to increasingly complex reaction systems. The main challenge of catalyst selection and use is the need to better control which product or products are formed (selectivity). In this project, Professor Francisco Zaera of the University of California, Riverside is exploring the use of single-atom alloy (SAA) catalysts as a way to improve reaction selectivity. This new class of catalysts is a new and promising approach towards both high selectivity and high activity in important classes of industrially reactions. The ability to promote the selective hydrogenation of chemical compounds promises to impact processes in the food, cosmetics, pharmaceuticals, and fine chemicals industries. In general, more selective catalytic processes lead to important benefits such as lower raw material consumption, increased efficiency, and waste minimization - all requirements for more environmentally-friendly processes. The knowledge derived from Zaera's research is used to illustrate basic principles in kinetics, catalysis, and materials synthesis in undergraduate and graduate classes. Professor Zaera is collaborating extensively with Latin American research groups. He encourages student participation from groups underrepresented in research. With funding from the Chemical Catalysis Program of the Division of Chemistry, Professor Francisco Zaera of the University of California, Riverside is developing a fundamental understanding of how single-atom alloy (SAA) catalysts function, with special focus on the use of CuPt bimetallics to promote the selective hydrogenation of unsaturated hydrocarbons. His main hypothesis is that, rather than acting as isolated single atoms as the present state-of-the-art research suggests, the single atoms of the minority component (Pt) may alter the electronic properties of the surface atoms. The Zaera group is probing this idea by following two parallel experimental approaches. His group studies model systems using high-flux molecular beams to emulate the atmospheric pressure conditions needed for catalysis. The team is employing a so-called "high-pressure cell" to carry out in-situ reflection-absorption infrared spectroscopy (IR) experiments during catalysis. Professor Zaera also studies realistic supported catalysts under catalytic conditions, performing in situ IR titrations to identify and quantify the Pt atoms that may segregate to the surface. In-situ X-ray absorption (XAS) spectroscopy is used to evaluate any possible changes in the coordination sphere around the Pt atoms as well as the nature (oxidation state) of the Cu atoms. Professor Zaera emphasizes the recruitment of women and minorities including visiting international students and scholars from Latin America in STEM professions.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.

用于加速化学反应的固体催化剂在工业中非常普遍，大约80%的化学过程都使用固体催化剂。固体催化剂应用于日益复杂的反应体系。催化剂选择和使用的主要挑战是需要更好地控制形成哪些产物或产物（选择性）。在这个项目中，加州大学河滨分校的Francisco Zaera教授正在探索使用单原子合金（SAA）催化剂来提高反应选择性。这种新型催化剂在工业反应中具有高选择性和高活性，是一种很有前途的新方法。促进化合物选择性氢化的能力有望影响食品、化妆品、制药和精细化工行业的加工过程。一般来说，更具选择性的催化过程会带来重要的好处，如降低原材料消耗、提高效率和减少废物——这些都是对更环保的过程的要求。从Zaera的研究中获得的知识被用来说明动力学，催化和材料合成的基本原理，在本科和研究生课程中。Zaera教授正在与拉丁美洲的研究小组广泛合作。他鼓励那些在研究中未被充分代表的群体的学生参与。在化学系化学催化项目的资助下，加州大学河滨分校的Francisco Zaera教授正在发展对单原子合金（SAA）催化剂功能的基本理解，特别关注使用CuPt双金属来促进不饱和碳氢化合物的选择性加氢。他的主要假设是，少数成分（Pt）的单个原子可能改变表面原子的电子特性，而不是像目前最先进的研究表明的那样作为孤立的单个原子。Zaera小组正在通过两个平行的实验方法来探索这个想法。他的团队使用高通量分子束来模拟催化所需的大气压力条件，研究模型系统。该团队正在使用所谓的“高压电池”在催化过程中进行原位反射-吸收红外光谱（IR）实验。Zaera教授还在催化条件下研究实际负载催化剂，进行原位红外滴定，以识别和量化可能分离到表面的Pt原子。原位x射线吸收（XAS）光谱用于评估Pt原子周围配位球的任何可能变化以及Cu原子的性质（氧化态）。Zaera教授强调在STEM专业中招募女性和少数民族，包括来自拉丁美洲的访问国际学生和学者。该奖项反映了美国国家科学基金会的法定使命，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

Hydrogenation of Cinnamaldehyde on Cu(110) Single-Crystal Surfaces

• DOI: 10.1021/acs.jpcc.1c04474
• 发表时间: 2021-07
• 期刊: The Journal of Physical Chemistry C
• 作者: Bo Chen;F. Zaera

Catalyst consisting of Ag nanoparticles anchored on amine-derivatized mesoporous silica nanospheres for the selective hydrogenation of dimethyl oxalate to methyl glycolate

• DOI: 10.1016/j.jcat.2020.08.018
• 发表时间: 2020-11-01
• 期刊: JOURNAL OF CATALYSIS
• 影响因子: 7.3
• 作者: Dong, Guilin;Cao, Yueqiang;Zhou, Xinggui
• 通讯作者: Zhou, Xinggui

Adsorption, Thermal Conversion, and Catalytic Hydrogenation of Acrolein on Cu Surfaces

• DOI: 10.1016/j.jcat.2022.09.013
• 发表时间: 2022-09
• 期刊: Journal of Catalysis
• 影响因子: 7.3
• 作者: Mindika Tilan Nayakasinghe;R. Ponce Perez;Bo Chen;N. Takeuchi;F. Zaera

Adsorption of crotonaldehyde on metal surfaces: Cu vs Pt

巴豆醛在金属表面的吸附：Cu 与 Pt

• DOI: 10.1063/5.0040776
• 发表时间: 2021
• 期刊: The Journal of Chemical Physics
• 作者: Nayakasinghe, Mindika Tilan;Guerrero-Sánchez, Jonathan;Takeuchi, Noboru;Zaera, Francisco
• 通讯作者: Zaera, Francisco

Thermodynamics of Carbon Monoxide Adsorption on Cu/SBA-15 Catalysts: Under Vacuum versus under Atmospheric Pressures

• DOI: 10.1021/acs.jpcc.1c10722
• 发表时间: 2022-02
• 期刊: The Journal of Physical Chemistry C
• 作者: T. Han;Ilkeun Lee;Yueqiang Cao;Xinggui Zhou;F. Zaera