CuCrO₂ Delafossite: A Stable Copper Catalyst for Chlorine Production

Abstract

Kommt Zeit, kommt Rat: Seit der Einführung von CuCl2 für die HCl‐Oxidation durch Deacon im Jahr 1868 war die Suche nach einem stabilen Kupferkatalysator vergeblich geblieben. Kupferdelafossit, CuCrO2 (siehe Bild), erweist sich als außergewöhnlich stabil in Chlorierungen und eignet sich für eine dauerhafte Cl2‐Produktion ohne Metallverlust. Ein hochaktives CuCrO2‐CeO2‐Komposit wurde entwickelt, das eine kosteneffektive Methode für die Zurückgewinnung von Chlor ermöglicht.

Niobium: Activator and Stabilizer for a Copper‐Based Deacon Catalyst

“…Another approach is to stabilize Cu ions in specific crystal lattices that have a high resistance against bulk chlorination, such as the delafossite crystal structure 17. 18…”

An efficient Cu-K-La/γ-Al2O3 catalyst for catalytic oxidation of hydrogen chloride to chlorine

“…Supported CeO 2 catalyst showed the conversion of HCl of 70-75% for over 700 h under the reaction conditions of the molar ratio of O 2 to HCl of 4.15, T inlet = 633 K and P = 1 bar [11,12]. CuAlO 2 catalyst showed the conversion of HCl of about 25% for over 1200 h under the reaction conditions of the molar ratio of O 2 to HCl of 4, W/F 0(HCl) = 8.96 g h mol −1 , T = 653 K and P = 1 bar [13,14]. Ruthenium-based catalysts are efficient commercialized catalysts for Deacon process; however, the high and dramatically fluctuating market price of ruthenium will limit the large-scale industrialization in the future, so it is necessary to develop other non-noble metal catalysts with low cost to replace the rutheniumbased catalysts [2,15,16].…”

Can Gold be an Effective Catalyst for the Deacon Reaction?

“…They also studied Cr 2 O 3 which has higher activity and stability than Cu based catalyst but leads to formation of chromyl chloride [11]. Based on these studies they subsequently investigated a delafossite CuCrO 2 catalyst, which they found to be stable [12] but significantly less active than RuO 2 .…”