Synergy of CuO and CeO2 combination for mercury oxidation under low-temperature selective catalytic reduction atmosphere

Abstract

Synergy for low temperature Hg 0 oxidation under selective catalytic reduction (SCR) atmosphere was achieved when copper oxides and cerium oxides were combined in a CuO-CeO 2 /TiO 2 (CuCeTi) catalyst. Hg 0 oxidation efficiency as high as 99.0% was observed on the CuCeTi catalyst at 200 °C, even the gas hourly space velocity was extremely high. To analyze the synergistic effect, comparisons of catalyst performance in the presence of different SCR reaction gases were systematically conducted over CuO/TiO 2 (CuTi), CeO 2 /TiO 2 (CeTi) and CuCeTi catalysts prepared by sol-gel method. The interactions between copper oxides and cerium oxides in CuCeTi catalyst yielded more surface chemisorbed oxygen, and facilitated the conversion of gas-phase O 2 to surface oxygen, which are favorable for Hg 0 oxidation. Copper oxides in the combination interacted with NO forming more chemisorbed oxygen for Hg 0 oxidation in the absence of gas-phase O 2. Cerium oxides in the combination promoted Hg 0 oxidation through enhancing the transformations of NO to NO 2. In the absence of NO, NH 3 exhibited no inhibitive effect on Hg 0 oxidation, because enough Lewis acid sites due to the combination of copper oxides and cerium oxides scavenged the competitive adsorption between NH 3 and Hg 0. In the presence of NO, although NH 3 lowered Hg 0 oxidation rate through inducing reduction of oxidized mercury, complete recovery of Hg 0 oxidation activity over the CuCeTi catalyst was quickly achieved after cutting off NH 3. This study revealed the synergistic effect of the combination of copper oxides and cerium oxides on Hg 0 oxidation, and explored the involved mechanisms. Such knowledge would help obtaining maximum Hg 0 oxidation co-benefit from SCR units in coal-fired power plants.

In situ fabrication of CuO/UHMWPE nanocomposites and their tribological performance

“…The characteristic peaks at binding energies of 935.0 and 955.0 eV can be assigned to Cu 2p3/2 and Cu 2p1/2, respectively . The satellite peaks located at higher binding energy, which are the shakeup peaks of the core level signals of Cu 2p and can be assigned to 3d 9 configuration of the copper atoms, indicate the presence of CuO in the composite . The XP spectra of Cu 2p3/2 and Cu 2p 1/2 of 1CuO/UHMWPE prepared in this work is found a shift to the direction of high binding energy and presents an enhanced chemical state.…”

Role of Ceria in the Design of Composite Materials for Elemental Mercury Removal

“…The Hg 0 removal process could be described by the Langmuir‐Hinshelwood mechanism, with the active surface oxygen playing a significant role in Hg 0 oxidation process. Similar synergistic phenomena have also been observed over CuO‐CeO 2 , CuO‐CeO 2 /TiO 2 , and CoO x ‐CeO 2 /TiO 2 catalysts …”

Mechanism of Mercury Adsorption and Oxidation by Oxygen over the CeO2 (111) Surface: A DFT Study

“…The convention entered into force on 16 August 2017. Coal-fired power plants are regarded as major sources of atmospheric mercury emissions [7,8]. The latest version of the Emission Standard of Air Pollutants for Thermal Power Plant (GB13223-2011), released by the Ministry of Environmental Protection of China, set the limit for the emission of mercury and its compounds from coal-fired boilers to 0.03 mg/m 3 .…”