Taking the honeycomb selective catalytic reaction(SCR) catalysts exposed to high arsenic atmosphere in a coal-fired power plant as the research object

the denitration parameters such as the denitration efficiency

ammonia escape

activity and SO_2/SO_3 conversion rate were detected by bench-scale tests. Moreover

several instruments like the X-ray diffractometer(XRD)

the X-ray fluorescence spectrometer(XRF)

the pore volume aperture analyzer

the scanning electron microscope-energy diffraction spectrum(SEM-EDS)

the inductively coupled plasma-mass spectrometer(ICP-MS) and the Fourier transform infrared spectrometer(FTIR) were employed to characterize the physical and chemical properties of the catalyst. The results show that

the activities of the catalysts dropped by more than 30% after about 4 000 hours' service

which could not meet the design requirement of ammonia escape less than 3 mL/L at 80% denitrification efficiency. No crystal change or agglomeration of the catalyst caused by high temperature(415 ℃) was observed. The deposition of arsenic on surface and pores of the catalysts resulted in a significant decrease of the micro specific surface area and pore volume of the catalyst

causing blocking of the pore system

thus the activity of the catalyst reduced.