CDS&E: Multiscale Process Intensification of Direct Catalytic Hydrogenation of CO2 to Hydrocarbons via Cooperative Tandem Catalysis

目前正在进行重大的研究工作，以开发新的化学制造技术，这些技术有可能使能源和化学工业脱碳，保持美国在生产有价值的化学产品和运输燃料方面的突出作用。这种持续进步的关键是“强化”化学工艺的发展，它将传统上的多个处理步骤合并为一个单一的、多功能的操作，促进了能源节约和成本降低——这种工艺改进广泛适用于能源、化学品和其他制造部门。本研究项目中提出的催化剂和工艺设计方法也促进了模块化制造工艺的发展，提高了化工制造供应链的效率、灵活性、弹性和整体竞争力。随着最近国内页岩气生产的革命，使用新型催化系统的新途径可以有效地促进一系列反应（而不是单一反应），这将为页岩气转化的潜在破坏性过程强化技术打开大门，并为创造氢基经济开辟新途径。这个研究项目将支持在研究生和本科阶段招募传统上代表性不足的学生。他们计划开展一项拓展活动，向一年级至四年级的学生传授可持续设计的重要性。研究成果将纳入新的研究生课程。该项目将通过开发协同串联催化剂（促进化学反应序列而不是单一反应的催化剂），为过程强化的新方向奠定基础。具体来说，本研究将解决以下基本问题：在串联反应过程中，多种催化剂如何在微观、中观和宏观/过程尺度上相互作用并影响单个催化性能？什么时候需要串联催化？如何预测串联催化剂的最佳组合？如何设计、合成和调整多催化系统以进行一系列反应，同时在工艺水平上确保所需的产品质量、稳定性和性能？作为一个具有代表性的串联催化系统，二氧化碳在金属氧化物上加氢生成甲醇将与沸石框架相结合，选择性地将甲醇转化为C2+化学产品，特别是C2- c4烯烃和C5-C18碳氢化合物。二氧化碳与H2的化学转化为燃料、化学品或化学前体是实现可持续化学品生产和加速“绿色能源”转型的概念演变。为了更好地理解反应化学物质之间的相互作用和串联催化，研究小组计划在密度泛函理论（DFT）水平上建立、验证和分析机理模型，并将DFT模拟结果转化为微动力学模型的速率和平衡常数。为了阐明微观变化如何影响串联催化剂体系的宏观性质，将制定一种基于序参数分析的独特方法（最初是在研究相变的背景下开发的），以减少多尺度反应器模型的复杂性。了解催化剂的性质如何影响反应过程的合并，将有助于强化过程的设计和控制，从而为新化学产品的发现节省大量的时间和投资。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。

Significant research efforts are currently underway to develop new chemical manufacturing technologies that have the potential to decarbonize the energy and chemical industries, maintaining the prominent role of the U.S. in producing valuable chemical products and transportation fuels. Key to this continuing advance is the development of “intensified” chemical processes that combine what traditionally were multiple processing steps into a single, multifunctional operation, facilitating energy savings and cost reductions - process improvements that have broad applicability to energy, chemicals, and other manufacturing sectors. The catalyst and process design methods proposed in this research program also facilitate the development of modular manufacturing processes, increasing the efficiency, flexibility, resilience, and overall competitiveness of chemical manufacturing supply chains. With the recent revolution in domestic shale gas production, new routes to using novel catalytic systems that effectively promote a sequence of reactions (rather than a single reaction) will open the door to potentially disruptive process intensification technologies for shale gas conversion and new pathways to creating a hydrogen-based economy. This research program will support the recruitment of traditionally underrepresented students both at the graduate and undergraduate levels. An outreach activity is planned that will teach the importance of sustainable design to 1st–4th graders. The research findings will be integrated into a new graduate-level course.This project will establish the foundation of a new direction in process intensification through the development of cooperative tandem catalysts, catalysts that promote sequences of chemical reactions rather than a single reaction. Specifically, this research will address the following fundamental questions: How do multiple catalysts interact and affect individual catalytic performances in a tandem reactive process at the micro-, meso- and macro/process-scales? When is tandem catalysis desirable? How can the optimal combinations of tandem catalysts be predicted? How are multi-catalytic systems designed, synthesized, and tuned to perform a series of reactions while ensuring the desired product quality, stability, and performance at the process level? As a representative tandem catalytic system, hydrogenation of CO2 over metal oxides to produce methanol will be integrated with zeolite frameworks that selectively transform methanol to C2+ chemical products, specifically C2-C4 olefins and C5-C18 hydrocarbons. Chemical transformation of CO2 with H2 into fuels, chemicals, or chemical precursors constitutes a conceptual evolution in achieving sustainable chemical production and expediting the “green energy” transition. To better understand the interactions among reaction chemical species and the tandem catalysis, the research team plans to develop, validate, and analyze mechanistic models at the density functional theory (DFT) level and translate the results of the DFT simulations into the rate and equilibrium constants of microkinetic models. To elucidate how microscopic changes affect the macroscopic properties of a tandem catalyst system, a unique method based on order parameter analysis (originally developed in the context of studying phase transitions) will be formulated to reduce the complexity of the multi-scale reactor models. Understanding how the properties of catalysts influence the merging of reaction processes will facilitate the design and control of intensified processes, thereby saving significant time and investment for new chemical product discovery.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.