Kinetics and constraints of CO oxidation over hexameric copper nanocluster catalyst supported on carboxyl-functionalised MWCNT at high temperatures

Publication date: 1 June 2020Source: Chemical Engineering Journal, Volume 389Author(s): Luqmanulhakim Baharudin, Isaac Severinsen, Alex C.K. Yip, Vladimir B. Golovko, Matthew J. WatsonAbstractKinetics of CO oxidation over hexameric copper nanoclusters supported on carboxyl-functionalised multi-walled carbon nanotubes (Cu6/MWCNTCOOH) was studied between 400 and 475 °C. An excessive amount of O2 in the feed gas hindered access of CO molecules to the active sites (maximum CO conversion ~29% in O2-rich environment (CO:O2 = 1:10 v/v) cf. ~89% in O2-lean environment (CO:O2 = 1.0:1.2 v/v) at GHSV of 3,000–6,000 mL/(gcat·h)). The reaction temperature range was constrained by catalyst deactivation due to the formation of CuCO3 below the lower limit, and combustion of the MWCNT support in the oxidative environment above the upper limit. A kinetic model was developed based on assumptions that the reaction was CO-adsorption limited and followed the Langmuir–Hinshelwood mechanism for CO concentrations ≤14 vol% in the feed gas. The activation energy (Ea) was determined to be 54.3 kJ/mol in the temperature range studied.Graphical abstract
Source: Chemical Engineering Journal - Category: Chemistry Source Type: research