Mn/Ce@HKUST-1 for Efficient Removal of Gaseous Thallium: Insights from Kinetic and Experimental Studies

Gaseous thallium (Tl) pollution events, primarily caused by nonferrous mineral refineries and fossil fuel combustion, have increased over the past few decades. To prevent gaseous Tl distribution from flue gas, MnO2/CeO2@ HKUST-1 (MCH) was synthesized and found to achieve a gaseous Tl(I) removal level of up to 90% at 423 K, a weight hourly space velocity (WHSV) of 2000 h(-1)/ mL with an Mn dose of 10%, maintained over 10 h. The best Mn/Ce ratio was found to be 9:1. To further investigate surface kinetic behavior, four commonly used kinetic models were applied, including the Eley-Rideal (ER) model, Langmuir-Hinshelwood (LH) model, Mars-van Krevelen (MVK) model, and pseudo-first-order (PFO) model. While the ER and LH models had the slightest deviation, the MVK model was the most reliable. The CatMAP software was also used to match the simulation deviation. This work demonstrated the Tl removal mechanism and provided insights into the accuracy of kinetic models on minor radius heavy metal. Thus, this research may help promote the design of reactors, heavy metal removal rates, and flue gas purification technology selection.

Automated summary

Gaseous thallium (Tl) pollution events caused by nonferrous mineral refineries and fossil fuel combustion have increased. The synthesized MnO2/CeO2@ HKUST-1 (MCH) achieved a 90% removal rate of gaseous Tl(I) at 423K and a weight hourly space velocity (WHSV) of 2000 h(-1)/ mL with a 10% Mn dose for 10 hours. Among the four kinetic models applied, the Mars-van Krevelen (MVK) model showed the most reliable results.