CAREER: Heterogeneous Catalytic Oxidation and Adsorption of Mercury Vapor: Integrated Research and Education in Air Pollution Control

职业：汞蒸气的多相催化氧化和吸附：空气污染控制的综合研究和教育

• 批准号: 1151017
• 负责人: Joo-Youp Lee
• 金额: $ 41.7万
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1151017&HistoricalAwards=false
• 关键词: CAREER; Heterogeneous; Catalytic; Oxidation; Adsorption

1151017 - LeeMercury is a toxic and persistent pollutant that bio-accumulates in the food chain. Human exposure to mercury occurs primarily by consumption of contaminated fish. Mercury in the environment is transformed into more toxic methylmercury; consumption of methylmercury may cause neurotoxic effects. Children and particularly developing fetuses are especially susceptible to methylmercury effects. A USEPA proposed rule, Mercury and Air Toxics Standards, requires coal- and oil-fired power plants to use maximum available control technology to reduce the emissions of mercury and other hazardous air pollutants as of 2016. Among elemental, oxidized, and particulate-bound mercury species present in flue gas, elemental mercury (Hg(0)) is most difficult to control because of its low concentrations, low reactivity with other flue gas components via homogenous oxidation, and low solubility in water. This CAREER research plan will significantly advance the knowledge and fundamental mechanistic understanding of heterogeneous catalytic oxidation and adsorption using the reactions between Hg(0) vapor and transition metal chlorides. A detailed mechanistic study will be conducted to investigate the cyclic Deacon reaction involving transition metal chlorides for Hg(0) oxidation. Transition metal chlorides are proposed to be more effective in Hg(0) oxidation than metal oxides since they can readily eliminate the rate-limiting competitive HCl adsorption step. The reaction of Hg(0) with transition metal chlorides is a catalytic reaction such that chloride is consumed to form readily soluble and adsorbable HgCl2. The metal lowers the activation energy barrier for the oxidation reaction. This will lead to the further development of metal chloride-based modified selective catalytic reduction materials for simultaneous NOx reduction and Hg(0) oxidation, Hg(0)-specific catalysts, and sorbents. This proposed research will enhance the capability to predict Hg(0) removal based on a fundamental understanding of physical and chemical principles. It will ultimately lead to advanced scientific knowledge and enhanced mercury control options needed for proposed mercury emission control regulations. It will also lead to various environmental remediation and separation technologies based on heterogeneous catalysis, adsorption, and absorption. The educational plan will provide co-benefits for chemical and environmental engineering faculty, students, and professionals in the areas of environmental catalysis, separation, and air quality/air pollution control. All of these efforts will ultimately increase awareness of mercury as a global pollutant and of best management practices for its control in flue gas emissions.

1151017-汞是一种有毒的持久性污染物，在食物链中生物积累。人类接触汞主要是通过食用受污染的鱼造成的。环境中的汞转化为毒性更大的甲基汞；食用甲基汞可能会造成神经毒性影响。儿童特别是发育中的胎儿特别容易受到甲基汞效应的影响。美国环保局提出的一项名为汞和空气有毒物质标准的规定，要求燃煤和燃油发电厂使用最大限度的可用控制技术，从2016年起减少汞和其他有害空气污染物的排放。在烟气中存在的元素汞、氧化汞和颗粒结合汞中，元素汞(Hg(0))最难控制，因为它的浓度低，通过均相氧化与其他烟气组分的反应活性低，在水中的溶解度低。这一职业研究计划将极大地促进对利用汞(0)蒸气和过渡金属氯化物之间的反应进行多相催化氧化和吸附的知识和基本机理的理解。对过渡金属氯化物参与的汞(0)氧化的循环Deacon反应进行了详细的机理研究。过渡金属氯化物被认为比金属氧化物更有效地氧化汞(0)，因为它们可以很容易地消除限速竞争HCl吸附步骤。汞(0)与过渡金属氯化物的反应是一种催化反应，使氯化物被消耗以形成易溶解和可吸附的HgCl2。金属降低了氧化反应的活化能垒。这将导致基于金属氯化物的同时用于NOx还原和汞(0)氧化的改性选择性催化还原材料、汞(0)专有催化剂和吸附剂的进一步发展。这项拟议的研究将增强基于对物理和化学原理的基本理解来预测汞(0)去除的能力。它最终将导致先进的科学知识和更好的汞控制选择，以满足拟议的汞排放控制条例的需要。这也将导致基于多相催化、吸附和吸收的各种环境修复和分离技术的出现。该教育计划将在环境催化、分离和空气质量/空气污染控制领域为化学和环境工程教师、学生和专业人员提供共同利益。所有这些努力最终将提高人们对汞作为一种全球污染物的认识，以及对其控制烟道气排放的最佳管理做法的认识。