Non-oxidative dehydrogenation of propane and isobutane over unconventional ZrO2- or TiO2-based catalysts: Understanding the role of coordinatively unsaturated metal cations

使用非常规 ZrO2 或 TiO2 基催化剂进行丙烷和异丁烷的非氧化脱氢：了解配位不饱和金属阳离子的作用

• 批准号: 339220402
• 负责人: Privatdozent Dr. Haijun Jiao
• 金额: --
• 依托单位: Leibniz-Institut für Katalyse e. V. an der Universität Rostock (LIKAT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/339220402?language=en
• 关键词: Non; oxidative; dehydrogenation; propane; isobutane

Non-oxidative dehydrogenation of propane and isobutane to the corresponding olefins are established large-scale processes that, however, faces challenges, particularly in catalyst development, which are toxicity of chromium compounds and high cost of platinum. To address these challenges, this proposal will deal with development of environmentally friendly and cost-efficient catalysts based on bulk materials (ZrO2 and TiO2). In comparison with typical supported catalyst, lattice defects on the surface of such catalysts are the catalytically active sites. They are coordinatively unsaturated metal cations (Mecus = Zr or Ti) located at oxygen vacancies. The main fundamental questions to be answered in this proposal are the effects of the host oxide (ZrO2 vs TiO2) and the metal oxide promoter (e.g. K2O, La2O3, or CeO2) used for creating anion vacancies in the host oxides on (i) formation of surface Mecus in the host oxides and (ii) the activity, on-stream stability and particularly selectivity (including coke formation) of Mecus in dehydrogenation of propane and isobutane. The alkanes were chosen both from fundamental and applied viewpoints. In comparison with propane/propene, isobutane and particularly isobutene (the desired product) can be isomerized to n-butane and linear butenes respectively. Therefore, it is important to elucidate if such isomers may open another pathways for formation of cracking products and carbon deposits. In order to understand the fundamentals of catalyst functioning on a level as elementary as possible, we will follow a complementary approach combining steady-state and transient catalytic tests as well as operando catalyst characterization with Density Functional Theory (DFT) calculations. In particular, the proposal is intended i) to establish structure-reactivity-selectivity relationships, which are the key factor for rational catalyst design as well as ii) to provide guidelines for an optimal production of propene and isobutene. The knowledge derived would permit to improve the efficiency of functionalization of raw materials in terms of saving natural resources and reducing harmful environmental impacts.

丙烷和异丁烷非氧化脱氢制烯烃的大规模工艺已经建立，但在催化剂开发方面面临挑战，特别是铬化合物的毒性和铂的高成本。为了应对这些挑战，本提案将涉及基于散装材料（ZrO2和TiO2）的环保和经济高效催化剂的开发。与典型负载型催化剂相比，这种催化剂表面的晶格缺陷是催化活性位点。它们是位于氧空位的配位不饱和金属阳离子（Mecus = Zr或Ti）。本提案中要回答的主要基本问题是用于在主氧化物中产生阴离子空位的主氧化物（ZrO2 vs TiO2）和金属氧化物促进剂（例如K2O， La2O3或CeO2）对(i)主氧化物中表面Mecus的形成和（ii） Mecus在丙烷和异丁烷脱氢过程中的活性，流上稳定性和特别是选择性（包括焦化）的影响。烷烃的选择从基本和应用的观点。与丙烷/丙烯相比，异丁烷，特别是异丁烯（期望产物）可以分别异构化成正丁烷和线性丁烯。因此，阐明这些异构体是否可能为裂化产物和碳沉积的形成开辟另一条途径是很重要的。为了在尽可能基本的水平上理解催化剂功能的基本原理，我们将遵循一种互补的方法，将稳态和瞬态催化测试以及操作性催化剂表征与密度泛函理论（DFT）计算相结合。特别是，该建议旨在i)建立结构-反应性-选择性关系，这是合理设计催化剂的关键因素，以及ii)为丙烯和异丁烯的最佳生产提供指导。从节约自然资源和减少有害环境影响的角度来看，所获得的知识将有助于提高原材料功能化的效率。