I-Corps: Support Promoted Low-temperature Emission Control Catalysts

I-Corps项目的更广泛影响/商业潜力是通过提高污染物排放气体在较低温度下转化为无污染气体的速度，减少车辆排放的污染物废气。目前用于此目的的汽车催化转化器由排放控制催化剂组成，在冷启动期间，由于冷启动温度低于催化剂的起燃温度，导致污染物排放到周围空气中，相对无效。本项目采用新型形状可控的氧化铈负载型排放控制催化剂，可在423 K以下实现90%的转化率，从而对环境和公共健康保护产生深远影响。此外，该项目对催化剂技术的支持将为设计高效和可持续的排放控制催化剂提供一种通用策略，从而降低价格，使催化转化器制造商具有竞争优势。这些低温排放控制催化剂也可以应用于许多废气净化应用，包括发电厂，炼油厂和化工厂，以及表面涂层设施。I-Corps项目进一步开发了一种技术，将形状控制合成氧化铈催化剂支持的纳米材料与通过化学蚀刻和等离子体处理的表面工程激活相结合。该技术代表了排放控制催化剂领域的重大进步：(1)调整氧化铈载体的形状，以获得更多的活性表面和可移动的氧在晶体表面上进行气体转化反应；(2)通过化学蚀刻提高氧化铈载体的表面缺陷浓度，以更好地捕获金属催化剂纳米团簇甚至单个原子，从而提高长期热稳定性/耐久性，减少贵金属的负载量；(3)利用等离子体处理激活金属-支撑界面。这些策略共同实现了催化剂-载体界面原子级结构和化学的微调，这可以为关键中间体的形成提供低能量障碍，并为低温下污染物气体转化提供开放的反应路径和活性位点。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。

The broader impact/commercial potential of this I-Corps project is to reduce emission of pollutant exhaust gases from vehicles by enhancing the conversion rate of pollutant emission gases to nonpolluting gases at lower temperature. Current automobile catalytic converters used for this purpose are comprised of emission control catalysts which are relatively ineffective during the cold start period because the cold start temperature is lower than the light-off temperature of catalysts, leading to pollutants emitted into the ambient air. The adoption of the novel shape-controlled cerium oxide supported emission control catalysts from this project will enable 90% conversion rate below 423 K, and thus have a profound impact on environmental and public health protection. In addition, the support promoted catalyst technology from this project will provide a generalizable strategy for the design of efficient and sustainable emission control catalysts with low-loading of costly precious metal catalysts, thereby leading to reduced prices and giving catalytic converter manufacturers a competitive advantage. These low temperature emission control catalysts may also be applied in many off-gas cleaning applications including in electrical power plants, refineries and chemical plants, and surface coating facilities.This I-Corps project further develops a technology that combines shape-controlled synthesis of cerium oxide catalyst support nanomaterials with surface engineering activation via chemical etching and plasma treatment. This technology represents a significant advancement to the field of emission control catalysts by: (1) tuning the shapes of cerium oxide support for obtaining more reactive surfaces and mobile oxygen species accessible on the crystal surface for gas conversion reactions; (2) increasing the surface defect concentration of cerium oxide support via chemical etching to better trap metal catalyst nanoclusters or even single atoms, thus leading to enhanced long-term thermal stability/durability and decreased loading amount of precious metals; and (3) activating metal-support interface using plasma treatment. Together these strategies enable fine tuning of the atomic-level structure and chemistry at the catalyst-support interface, which can offer low energy barriers for the formation of key intermediates and open reaction paths and active sites for pollutant gases conversion at lower temperature.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.