Room temperature efficient reduction of NOx by H2 in a permeable compounded membrane – Catalytic reactor

Abstract

A permeable compounded membrane-catalytic reactor is proposed and evaluated to remove NOx in simulated flue gas by H2. The flue gas denitrification could be achieved at room temperature spontaneously without extra energy input. In the reactor, the reducing agent H2 is recycled and separated from the simulated flue gas containing NO by a compounded membrane embedded with Pt–C catalyst, through which only H2 could permeate to efficiently reduce NO. The relevant experimental data show that the NO removal could reach close to 100% at room temperature with the influent concentration from 218ppm to 985ppm, with a very short residence time of 0.09s. The transmission electron microscopy (TEM) illustrates that the Pt nanoparticles are uniformly dispersed on carbon as cluster. The prepared Pt–C catalyst is described by Raman spectra, and further electron transfer from Pt to substrate carbon is observed via X-ray photoelectron spectroscopy (XPS). It is proved via both experimental data and DFT calculations that the electronic structure of Pt is modified due to the strong interaction between Pt and carbon in the prepared catalyst, at the same time, the high surface area of carbon ensures efficient capture NO and H2, which gives rise to synergetic chemical coupling effect accounting for the surprisingly performance of Pt/C catalyst coated on carbon paper. The effects of the operating parameters on the removal for the proposed reactor, such as the residence time, initial NO concentration, and NO:H2 flow rate ratio, are also analyzed.