Impact of Mn addition on catalytic performance of Cu/SiBEA materials in total oxidation of aromatic volatile organic compounds

Abstract

Dealuminated BEA zeolite (SiBEA) was chosen as a support of metal oxide(s) phase for catalytic combustion of volatile organic compounds (VOCs). Copper and/or manganese oxide(s) were deposited at various Cu/Mn molar ratios. Factors influencing the catalytic activity were found by chosen physicochemical methods, including XRD, XRF, lowtemperature N 2 adsorption, FT-IR, UV-Vis-DRS, STEM-EDX, XPS and H 2 -TPR. Depending on the chemical composition, CuO, (Cu x Mn 3-x ) 1-δ O 4 , Cu-doped Mn 3 O 4 or Mn 2 O 3 was formed as the dominant phase. The active phase particles were located mainly in the interparticle voids of the zeolite support. SiBEA gained Lewis acid sites after the introduction of the metal oxide phase, especially in the case of CuO deposition. The presence of copper in the catalytic system resulted in enhanced reducibility of the active phase, and in a consequence in high catalytic activity in the total oxidation of aromatic VOCs, which proceeds according to the Mars-van Krevelen mechanism. After the introduction of Mn, the co-existence of different valence forms was found due to the redox equilibrium: Cu 2+ + Mn 3+ = Cu + + Mn 4+ .

Pt Nanoparticles on Beta zeolites for Catalytic Toluene Oxidation: Effect of the Hydroxyl Groups of Beta Zeolite**

“…However, it is worth noting that, compared to the catalyst supported by H‐Beta (i. e., CoO x /H‐Beta), the CoO x /deAl‐Beta catalyst showed very similar conversion of toluene and yield of CO 2 and CO. Similarly, highly dispersed bimetallic CuMnO x phases were supported on deAl‐Beta as well by varying the Cu/Mn ratio during impregnation [27] . The mixed oxides catalysts with increased surface oxygen vacancies showed a better catalytic performance than the monometallic catalysts (i. e., Cu/deAl‐Beta and Mn/deAl‐Beta).…”

“…Recent studies also demonstrated the successful development of supported metal catalysts on deAl‐Beta for catalytic oxidation of toluene including monometallic CoO x /deAl‐Beta [26] and bimetallic CuMnO x /deAl‐Beta, [27] in which a homogeneous distribution of the active phases over the support was achieved. For example, highly dispersed isolated mononuclear Co(II) species, small Co(II) oxide clusters and/or Co 3 O 4 crystallites were incorporated into the framework of Beta zeolite by changing the amount of the introduced Co from 3 to 9 wt.…”

“…[24] The silanol nests in the mesoporous MFI zeolite (after removal of gallium, deGa) could activate the hard-to-reduce rare-earth elements (e. g., La and Y with low reduction potential) effectively by arranging them as single atomic species to overcome the energy hurdle, which facilitates the formation of alloy NPs. [25] Recent studies also demonstrated the successful development of supported metal catalysts on deAl-Beta for catalytic oxidation of toluene including monometallic CoO x /deAl-Beta [26] and bimetallic CuMnO x /deAl-Beta, [27] in which a homogeneous distribution of the active phases over the support was achieved.…”

Efficient toluene low‐temperature elimination over manganese oxides: Unveiling the decisive role of lattice oxygen

“…[7,8] As catalysts are the most critical element of catalytic oxidation, it is extremely important to provide an affordable, effective, and simple catalyst for the elimination of VOCs. [9,10] Metal oxides have become one of the most important materials in catalytic oxidation processes due to their stability and potent oxidation capacity, such as Mn, [11] Co, [12] Cu, [13] and Fe. [14] As compared with other transition metal oxides, manganese-based oxides have superior catalytic performance in the catalytic oxidation of VOCs due to their adaptable crystal type, valence, and morphology.…”

“…Metal oxides have become one of the most important materials in catalytic oxidation processes due to their stability and potent oxidation capacity, such as Mn, [ 11 ] Co, [ 12 ] Cu, [ 13 ] and Fe. [ 14 ] As compared with other transition metal oxides, manganese‐based oxides have superior catalytic performance in the catalytic oxidation of VOCs due to their adaptable crystal type, valence, and morphology.…”