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

Abstract

A highly active Cu‐based Deacon catalyst with an enhanced lifetime was developed by combining two corrosion‐resistant high‐throughput reactor setups in this combinatorial study. Catalyst activities were studied in a sequential 10‐fold reactor equipped with online MS. For accelerated catalyst ageing studies, a parallel 10‐fold reactor was used. The starting point was a CuTi mixed‐metal oxide found in former discovery investigations. As development criteria, catalyst stability and HCl conversion were selected. The amount of Cu in the CuTi catalysts were analyzed before and after the ageing process by X‐ray fluorescence spectroscopy. Dopant elements were selected that are reported to form oxides with a high corrosion resistance against gaseous HCl. Our study revealed that doping with 1 mol % Nb reduced the Cu leaching during the reaction. Furthermore, the activation energy was decreased by Nb, which enhanced the chlorine production.

Corrosion‐Resistant Parallel Fixed‐Bed Reactors for High‐Throughput Screening of New Deacon Reaction Catalysts

“…The Cu 10 Ti 90 O x catalyst is stable in the first 24 h and the decrease of the conversion is below the measurement error. The performance of this catalyst has been studied in long‐term measurements over 100 h and the results were published recently 45. These studies confirm the usefulness of tenfold reactor systems for reaction performance study over time as well as for ageing studies 44, 45.…”

HCl Oxidation To Recycle Cl2 over a Cu/Ce Composite Oxide Catalyst. Part 2. Single-Tube-Reactor Simulation

“…(13) The specific heat capacity, viscosity, density of molten salt, and heat-transfer coefficient of molten salt λ m (kJ·m −1 ·s −1 ·K −1 ) in eq 13 are referenced from the literature. 28,29 The heat capacity of the mixed gas at constant pressure C p (kJ·kmol −1 ·K −1 ) in eq 9 is calculated by eq 14.…”

“…17−19 However, catalyst loss caused by particle attrition and low production capacity due to back-mixing of the substances in the fluidized bed lead to increased complexity and cost. 13 Compared to the fluidized-bed reactor, fixed-bed reactors can achieve a higher conversion per pass and reduce operational costs. However, it is difficult to cope with the large amount of reaction heat generated in a fixed-bed reactor.…”

Reaction Kinetics of HCl Catalytic Oxidation over a Supported Cu-Based Composite Industrial Catalyst

“…Researchers generally studied this problem from two perspectives: (1) improvement of catalyst stability and activity and (2) optimization of reactor and reaction conditions. For the first perspective, catalysts generally used in HCl catalytic oxidation, including Cu-, Cr-, Ru-, and Ce-based composite catalysts, were studied to increase the stability and decrease the activity temperature. − Sun et al studied the CuKSm x compound catalyst, and their results showed that addition of SmCl 3 promoted dispersion of copper species and provided more active sites of copper species, which increased the catalytic activity of the CuKSm x catalyst. Feng et al studied Cu–K–La/γ-Al 2 O 3 catalysts, and their results showed that Cu, K, and La species highly dispersed on the surface of γ-Al 2 O 3 and addition of KCl provided more active sites of Cu 2+ species and improved the catalytic activity and stability.…”