Abstract
A series of germanium-based Keggin-type polyoxometalates (POMs), including H4GeW12O40 (HGeW), H5GeW11VO40 (HGeWV), H5GeMo11VO40 (HGeMoV) and H5GeW9Mo2VO40 HGeWMoV), were first synthesized and utilized as catalysts for removal of NOx. The fourier transform infrared spectroscopy (FT-IR) and temperature-programmed desorption-mass spectroscopy (TPD-MS) characterizations were carried out to investigate the adsorption-desorption behavior and decomposition mechanism of NOx. The adsorption experiments revealed that HGeW had the highest NOx adsorption capacity up to 16.2 mg NOx per gram catalyst. Two infrared characteristic bands appeared at 2210 and 1851 cm−1 after NOx adsorption, while the latter firstly discovered over NOx-absorbed POMs could be assigned to nitrosyl radical (NO·). The regeneration of HGeW could be realized via reducing the temperature in wet atmosphere to desorb NOx. TPD-MS was conducted to investigate the decomposition behavior of NOx over HGeW and tungstophosphoric acid (HPW). O2 was firstly detected among the decomposition products, besides N2 and N2O. According to conservation calculation based on N mass, NOx removal rate of 81.5 % and N2 selectivity of 68.3 % could be achieved for HGeW. While the NOx conversion rate and N2 selectivity for HPW reached 54.1 % and 53.4 %, respectively.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
