In the United States, Rajadurai began his career at the University of Notre Dame and worked also in a number of advanced laboratories around the nation. His associates included J. J. Carberry and C.B. Alcock, with whom he collaborated and developed non-noble metal catalyst and solid oxide solutions, including one rivaling platinum for oxidation and reduction reactions. He developed organic free radicals for polymerization-initiating reactions and studied the photochemical/physical properties using single and dual LASER. Rajadurai transitioned to corporate business in 1990, with a series of senior scientist and executive positions. At Carus Chemicals, he was responsible for generating catalyst formulation process, and developed patents for ozone decomposition catalyst and powder coating techniques. Rajadurai directed Molecular Technology Corporation catalyst development, reactor designs, and analytical procedures – resulting in solutions for nitrogen oxide reduction systems applied in diesel and natural gas operated engines. As a Research Leader of Cummins from 1990 to 1995, Rajadurai developed catalytic aftertreatment systems for diesel engines and was responsible for management of industrial-university catalytic research programs around the United States to investigate quantum chemical modeling for catalyst prediction and microwave-generated free radical injections for nitrogen oxide reduction. While at Tenneco, he established computational simulation for exhaust after treatment system development for the commercial, heavy duty specialty and global emerging markets. His responsibility included North American manufacturing of the ultra thinwall substrate catalytic converter working with Corning Inc. and NGK. He received Tenneco Innovation Award by recognizing product & process innovation for the development of low noble metal catalytic converter in 1998, Tenneco Automotive General Manager’s Leadership Award in 1998 to honor of stellar performance in leadership role and exceptional teamwork, Tenneco Automotive Vision Award in the year 2000 for pioneering global ideas for Cleaner, Quieter and Safer transportation. He was elected as Board of Director of the World's leading Manufacturers of Emission Control Association, Board of Director of US Fuel Cell Council to develop a clean energy solutions for future, Board of Director of Walker Exhaust India Private Limited in 2001. While an executive at ArvinMeritor, Rajadurai directed the technology road map, annual operating plan and business strategy. Rajadurai was Vice President of ACS Industries from 2004 to 2009, in-charge of the strategic planning for product and technology development of wire mesh catalyst infrastructure. Rajadurai is an elected fellow of the Society of Automotive Engineers.
Rajadurai received SAE India Southern Section Lifetime Accomplishment Award in 2017 for his contribution on automobile product and process innovation & design for competitive advantage. He received Dr. K.C.G. Verghese Excellence Award in 2017 from Hindustan Group of Institutions for his Research Achievements. He received Bharat Gaurav National Award for his outstanding excellence and remarkable achievements in the field of Teaching, Research & Publications from IRDP Group of Journals in 2020.
He has presented several research findings in International conferences such as Diesel Engine-Efficiency and Emissions Research Conference, International Conference for Solar Conversion, Fifth National Catalysis Symposium, Society Automotive Engineers Congress International Conference on Automotive Materials & Manufacturing, FISITA, Asian PowerTrain Conference, GT Conference.