Effect of Promotion with Ru Addition on the Activity and SO₂ Resistance of MnO_x–TiO₂ Adsorbent for Hg⁰ Removal

Abstract

In order to investigate the promotional effects of ruthenium (Ru) addition on the structure, activity, and SO2 resistance of MnO x –TiO2 mixed-oxide adsorbent for Hg0 removal at lower temperature, the Ru modified MnO x –TiO2 (RMT) adsorbent, MnO x –TiO2 (MT), and RuO2–TiO2 (RT) were synthesized by the sol–gel method. The fresh and spent adsorbents were characterized by N2 physisorption, XRD, FTIR, H2-TPR, XPS, TG-DSC, and SO2-TPD. It was found that the addition of Ru oxide not only can increase the activity of Hg0 removal but also can significantly enhance their SO2 resistance performance. The amorphous structure and some synergistic effects among Ru, Mn and oxygen species may play key roles in promoting Hg0 removal and superior performance of SO2 tolerance. Although RMT exhibited an excellent SO2 resistance performance for Hg0 capture, some active sites would be destroyed with as high as 2500 ppm of SO2 introduced. The sulfate species deposited on the surface of poisoned adsorbent and the consumption of active MnO x and RuO2 by SO2 had a negative activity for Hg0 removal. The enhanced effect of Ru modified MnO x –TiO2 adsorbent on SO2 resistance could be derived from the selective formation of sulfate species on Ru. The possible mechanism of Ru addition on the SO2 resistance of MnO x –TiO2 mixed-oxide adsorbent has also been proposed.

Ruthenium Oxide Incorporated One‐Dimensional Cobalt Oxide Composite Nanowires as Lithium–Oxygen Battery Cathode Catalysts

“…The broad peak at approximately 25° corresponds to the tape that supported the samples. For the RuO 2 /Co 3 O 4 NWs, the diffraction peaks for the RuO 2 phase are obscured, possibly owing to the small amount of RuO 2 added to the Co 3 O 4 NWs and/or the good dispersion of Ru oxide in the Co 3 O 4 matrix …”

Removal of NO by catalytic decomposition of vaporized H2O2 over Mo–Fe/TiO2 catalyst

“…13, the 2%Fe/TiO 2 catalyst exhibited three desorption peaks in the temperature ranges 100 to 300 °C, 350 to 700 °C and 750 to more than 1000 °C, which can be attributed to weakly and physically adsorbed SO 2 , moderately bonded sulfate species and strongly bonded sulfate species, respectively 44 . The peak at 228 °C corresponded to the physically adsorbed SO 2 on the catalyst surface, 45,46 the shoulder peak positioned at 653 °C could probably be attributed to the decomposition of sulfated titania (TiO 2 –SO 4 2− ) 47 and the high‐temperature peak located at 938 °C was assigned to SO 2 chemically adsorbed in the catalyst bulk 46,48 . However, for the 1.5%Mo–0.5%Fe/TiO 2 catalyst, only two desorption peaks were observed.…”

Investigation on Simultaneous Removal of SO2 and NO over a Cu–Fe/TiO2 Catalyst Using Vaporized H2O2: An Analysis on SO2 Effect

“…The peaks at around 220 °C were ascribed to the physical absorption of SO 2 molecules on the surface of the catalysts. The peaks at 560 and 598 °C were ascribed to the formation of CuSO 4 species on the 1% Cu–1% Fe/TiO 2 . , The peaks at 653 and 687 °C were assigned to the strong adsorption between TiO 2 and SO 2 on the catalyst surface. , The above four peaks belonged to the sulfate species with moderate adsorption strength. The peaks at 914 and 938 °C were attributed to the strongly bound sulfates with the interior of the catalyst cell, , which could destroy the structure of the catalyst.…”

“…TiO 2 possessed the advantages of large specific surface area, excellent chemical stability, and abundant reserves and was regarded as a promising catalyst for simultaneous removal of NO x and SO 2 . Recent studies have shown that the introduction of Fe on the TiO 2 could significantly enhance the catalytic activity in the decomposition of H 2 O 2 for simultaneous removal of NO x and SO 2 . , However, the excellent NO x removal efficiency was obtained with large consumption of H 2 O 2 .…”