Catalytic Combustion of Ammonia as a Zero-Carbon Fuel: Catalyst Design and Mechanistic Studies

作为一种成熟的商品，氨（NH3）可以很容易地由可再生资源制成，它提供了一种环境可持续和低成本的方式，可以从化石燃料过渡到清洁，低碳和可再生能源的未来。技术挑战是有效燃烧NH3，同时由于燃料中极低的火焰速度、窄的可燃性和高氮含量而具有低氮氧化物（NOx）排放。催化燃烧提供了一种有前途的技术来燃烧氨，其不受火焰速度、可燃性极限的限制，并且具有低的燃烧温度以抑制热NOx的形成。因此，需要开发廉价而有效的燃烧催化剂。燃烧催化剂应当在低温下具有足够的活性以用于启动，并且能够在高温下维持活性和机械完整性，并且在NH3燃烧中具有可忽略的NOx形成。本研究提出将自诱导电化学促进现象引入到廉价过渡金属氧化物燃烧催化剂的设计中，通过这项工作，新概念将被验证为一种新的燃烧催化剂设计策略，并揭示催化剂的潜在结构-性能关系。利用科学知识将能够开发有效的燃烧催化剂，以氨为燃料开启零碳经济。

A mature commodity that can be readily made from renewable resources, ammonia (NH3) offers an environmentally sustainable and low-cost means of transition from fossil fuels to a clean, low-carbon and renewable energy future. The technical challenge is to combust NH3 efficiently with low nitrogen oxides (NOx) emissions due to the extremely low flame speed, narrow flammability and high nitrogen content in the fuel. Catalytic combustion offers a promising technology to burn ammonia which is not constrained by the flame speed, flammability limits and have low combustion temperature to supress thermal-NOx formation. Development of cheap yet effective combustion catalysts is therefore needed. The combustion catalysts should be sufficiently active at low temperature for start-up and are able to sustain activity and mechanical integrity at high temperature and has negligible NOx formation in NH3 combustion. This research proposes to incorporate self-induced electrochemical promotion phenomena into the design of combustion catalysts using cheap transition metal oxides, and through this work, the new concept will be validated as a new combustion catalyst design strategy and the underlying structure-performance relationships of catalysts will be revealed. The scientific knowledge to be harnessed will enable the development of effective combustion catalysts to unlock a zero-carbon economy using ammonia as a fuel.