Rath Tobias, Uhrich Andrej, Lüken Alexander, Zhao Guixia, Rittermeier André, Muhler Martin
Laboratory of Industrial Chemistry, Ruhr-University Bochum, 44780, Bochum, Germany.
Covestro (Deutschland) AG, 41540, Dormagen, Germany.
ChemSusChem. 2019 Jun 21;12(12):2725-2731. doi: 10.1002/cssc.201900642. Epub 2019 May 24.
We studied the photocatalytic aerobic oxidation of HCl over TiO for producing Cl . Steady-state Cl production rates were determined with a photocatalytic fixed-bed gas-phase reactor equipped with UV light-emitting diodes (LEDs) using iodometric titration as online analytics. We found stable Cl production rates of up to 16 mmol h m for commercial anatase TiO Hombikat UV100. The rate increased linearly with temperature from 21 to 140 °C, indicating the acceleration of the limiting desorption rate of the coupled product water. Comparing different TiO polymorphs revealed that anatase possesses higher activity than rutile. The adsorption of HCl was monitored in situ by IR spectroscopy. The IR spectra indicated that HCl chemisorption chlorinates the surface of TiO under the reaction conditions, suggesting it to be the first step of the reaction mechanism. High stability opens up the opportunity of developing a promising photocatalytic process of HCl recycling at lower temperatures suitable for reaching full conversion.
我们研究了在TiO上光催化有氧氧化HCl以生成Cl的过程。使用配备紫外发光二极管（LED）的光催化固定床气相反应器，并采用碘量滴定法作为在线分析手段，测定了稳态Cl生成速率。我们发现，对于商用锐钛矿型TiO Hombikat UV100，稳定的Cl生成速率高达16 mmol·h⁻¹·m⁻²。该速率在21至140°C范围内随温度呈线性增加，这表明耦合产物水的极限解吸速率加快。比较不同的TiO多晶型物发现，锐钛矿型比金红石型具有更高的活性。通过红外光谱原位监测HCl的吸附情况。红外光谱表明，在反应条件下，HCl化学吸附会使TiO表面氯化，这表明它是反应机理的第一步。高稳定性为开发一种有前景的光催化过程提供了机会，即在较低温度下进行HCl回收，以实现完全转化。
