CAREER: SusChEM: Development of Governing Mechanistic and Kinetic Models for the Selective Oxidative Cleavage of Levulinic Acid Over Supported Vanadium Oxides

摘要项目负责人：Jesse Q bond提案编号：1454346机构：Syracuse university本项目旨在研究利用生物质生产丁二酸和马来酸的策略。传统上，这些商品化学品是由原油或天然气的氧化成分制成的，这是具有挑战性的。相反，用糖分子更有效、更廉价地生产它们是可能的，糖分子可以从生物质中提取。这种方法需要我们理解为什么某些催化剂和前体能产生期望的产物，而另一些却不能。我们预计，将生物质和生物质衍生物转化为有价值产品的技术可以帮助生物质加工工业的商业发展。该项目的教育部分将通过服务项目建立雪城大学学生和雪城社区之间的联系。教育项目包括公共研讨会，旨在通过教育参与者有关能源和资源可持续性的主题来提高公众的科学素养。研讨会还将概述减少社会污染的有效方法。美国对化石资源和技术的依赖？美国在可持续发展中的作用。这些研讨会将由雪城大学的学生主持，作为他们本科课程的一部分。这些学生还将参与设计项目，将新的能源和资源效率技术纳入正在进行的城市发展计划。这将使他们能够利用他们的培训来改善他们的社区，并展示STEM教育的有益社会影响。该奖项支持双功能乙酰丙酸（4-氧戊酸）在负载型钒氧化物上气相有氧氧化裂解生成C4二酸的研究。在乙酰丙酸中，通过末端C-C键的断裂形成二酸，这在单功能酮类似物如2-戊酮中通常没有观察到。中心假设是乙酰丙酸的结构和双功能是与VOx位点独特相互作用的基础，这种相互作用将选择性转向末端C-C切割。该项目旨在确定在酮氧化过程中控制C-C裂解选择性的描述符。该项目将通过测量氧化酮在VOx/Al2O3催化剂上裂解的速率和选择性来考虑VOx形态的影响，其中VOx相和聚合程度由不同的钒负载控制。Brønsted和Lewis酸度的作用将通过研究单层VOx/Al2O3催化剂上的氧化裂解来检验，其中酸位密度和分布都使用酸性和碱性改性剂来改变。通过比较还原性不同的氧化物上的VOx位点，探讨V-O-X键性质的影响。利用18O进行同位素示踪可以确定晶格氧和化学吸附氧在乙酰丙酸氧化过程中的作用。酮的结构、空间相互作用和二级功能的影响将通过动力学和光谱研究的结合来探讨，这些研究将对比乙酰丙酸氧化与各种单功能和双功能酮类似物的氧化。电子结构计算将用于建立和参数化微动力学模型，这将调和第一原理的期望与实验结果。拉曼、UV-Vis、FTIR和温度编程光谱（如TPD、TPSR）将提供位点结构和化学功能的全面表征。

AbstractPI: Jesse Q BondProposal #: 1454346Institution: Syracuse UniversityThis project aims to develop a strategy for producing succinic acid and maleic acid from biomass. Traditionally, these commodity chemicals are made by oxidizing components of crude oil or natural gas, which is challenging. Instead, it may be possible to produce them more efficiently and inexpensively from sugar molecules, which can be extracted from biomass. This approach would require that we understand the reasons why certain catalysts and precursors deliver the desired products, while others do not. We anticipate that a technology that converts biomass and biomass derivatives to valuable products could help with commercial development of biomass processing industries. An educational component of the project will build a connection between Syracuse University students and communities in the city of Syracuse through service projects. The education program includes public workshops designed to improve public scientific literacy by educating participants on topics in energy and resource sustainability. Workshops will also outline effective methods for reducing society?s dependence on fossil resources and technology?s role in sustainability. The workshops will be facilitated by Syracuse University students as part of their undergraduate curriculum. These students will also work on design projects that incorporate new, energy- and resource-efficient technologies into ongoing urban development initiatives. This will allow them to use their training to improve their community and demonstrate the beneficial societal impacts of a STEM education.This award supports the study of gas-phase, aerobic oxidative cleavage of bifunctional levulinic acid (4-oxopentanoic acid) over supported vanadium oxides to yield C4 diacids. Diacid formation occurs through cleavage of the terminal C-C bond in levulinic acid, which is not generally observed in monofunctional ketone analogs, such as 2-pentanone. The central hypothesis is that the structure and bifunctionality of levulinic acid underlie unique interactions with VOx sites that shift selectivity toward terminal C-C cleavage. The project seeks to identify descriptors that govern C-C cleavage selectivity during ketone oxidation.This project will consider the influence of VOx speciation by measuring rates and selectivities of oxidative ketone cleavage over VOx/Al2O3 catalysts in which VOx phase and degree of polymerization are controlled by varying vanadium loading. The roles of Brønsted and Lewis acidity will be examined by studying oxidative cleavage over monolayer VOx/Al2O3 catalysts in which both acid site density and distribution are varied using acidic and basic modifiers. The influence of V-O-X bond character will be probed by comparing VOx sites on oxides that differ in reducibility. Isotopic tracing using 18O will identify the roles of lattice and chemisorbed oxygen during levulinic acid oxidation. Influences of ketone structure, steric interactions, and secondary functionality will be probed through a combination of kinetic and spectroscopic studies that contrast levulinic acid oxidation with that of various mono- and bifunctional ketone analogs. Electronic structure calculations will be used to build and parameterize a microkinetic model, which will reconcile first-principles expectations with experimental outcomes. Raman, UV-Vis, FTIR, and Temperature-Programmed spectroscopies (e.g., TPD, TPSR) will provide comprehensive characterization of site structure and chemical functionality.