Effect of Precious Metals on NO Reduction by CO in Oxidative Conditions

• Main Authors: Joudia Akil, Stéphane Siffert, Pirault-Roy Laurence, Damien P. Debecker, François Devred, Renaud Cousin, Christophe Poupin
• Format: Article
• Language: English
• Published: MDPI AG 2020-04-01
• Series: Applied Sciences
• Subjects: environmental chemistry; oxyfuel combustion; NO-CO reaction; heterogeneous catalysis
• Online Access: https://www.mdpi.com/2076-3417/10/9/3042

Carbon dioxide has become an environmental challenge, where the emissions have reached higher level than can be handled. In this regard, conversion of CO₂ to value-added chemicals and thus recycling of CO₂ appear a viable option. Prior to valorization, CO₂ must be purified. Among several opportunities, oxyfuel combustion is a process in rapid development. However, the gases resulting from this process contain some traces of impurities that can hinder the recovery of CO₂ such as NO and CO. This work has, therefore, focused on the study of the NO-CO reaction in an oxidizing medium, using heterogeneous catalytic materials based on various supported noble metals. These materials were extensively characterized by a variety of methods including Brunauer–Emmett–Teller (BET) surface area measurements, hydrogen chemisorption, transmission electron microscopy (TEM) and H₂ temperature programmed reduction (H₂-TPR). The results obtained show that the catalytic behavior of M/Al₂O₃ catalysts in CO oxidation and NO reduction with CO in oxidative conditions depends mainly on the nature of the metal. The best result for both reactions is obtained with Pt/Al₂O₃ catalyst. The Pt nanoparticles in their metallic form (Pt°) as evidenced by TPR could explain the activity.