Effect of Ordered Mesoporous Alumina Support on the Structural and Catalytic Properties of Mn−Ni/OMA Catalyst for NH₃−SCR Performance at Low‐temperature

Abstract

MnÀ Ni oxides supported on ordered mesoporous alumina (OMA) catalysts were applied to the NH 3 À SCR of NO x at lowtemperature compared with MnÀ Ni oxides supported on commercial γ-Al 2 O 3 . The NO x conversion and N 2 selectivity of MnÀ Ni/OMA were superior to the MnÀ Ni/γ-Al 2 O 3 in the temperature window of 90~240°C. BET, XRD, NH 3 À TPD, NO + O 2 À TPD, Pyridine-IR, H 2 À TPR, and XPS were performed to characterized the physicochemical properties of the catalysts. The characterization results manifested that supports conduct a significant part on the structural and catalytic properties of catalysts for NH 3 À SCR performance. Compared with MnÀ Ni/Al 2 O 3 , the super SCR performances of MnÀ Ni/OMA could be ascribed to not only the higher dispersion of MnO x but also more abundant Lewis acid sites, and the increase in redox capacity since the extremely primary MnO 2 phase on catalyst's surface. Furthermore, in situ DRIFTs were conducted to detect the SCR-reaction mechanism over the two catalysts. Results demonstrate that although the OMA support can greatly enhance the catalytic activity of MnÀ Ni/OMA catalysts, the reaction mechanism over MnÀ Ni/OMA does not alter in comparison with MnÀ Ni/Al 2 O 3 . Namely, the concurrence of Langmuir-Hinshelwood (LÀ H) and Eley-Rideal (EÀ R) mechanism, among which the EÀ R mechanism plays a dominant role.[a] Dr.

Enhanced Hydrogenation of Levulinic Acid over Ordered Mesoporous Alumina‐Supported Catalysts: Elucidating the Effect of Fabrication Strategy

“…It can be suggested that the OM‐supported catalysts exhibited more exposed surface hydroxy groups, hence the presence of the bands at 1540 cm −1 . Similar findings were also observed in previous studies [50] …”

Comparison of physicochemical properties and selective catalytic reduction activities of CeMn/TiO2 catalysts with and without phosphorus additives

“…A manganese oxide (MnO x ) SCR catalyst has been widely used for NO x removal because of its low cost, high thermal stability and higher SCR activity than other catalysts at low temperatures (Xu et al 2013). However, as MnO x loading amount increases agglomeration increases and MnO x is not dispersed perfectly on the catalyst surface (Liu et al 2016). Liu et al (2016) found that Mn-Ni/OMA exhibits higher NO x conversion performance than Mn-Ni/γ-Al 2 O 3 in the 90-240°C temperature window.…”

“…However, as MnO x loading amount increases agglomeration increases and MnO x is not dispersed perfectly on the catalyst surface (Liu et al 2016). Liu et al (2016) found that Mn-Ni/OMA exhibits higher NO x conversion performance than Mn-Ni/γ-Al 2 O 3 in the 90-240°C temperature window. Guo et al (2019) revealed that Mn-Eu-Fe catalyst with Fe/Mn molar ratio of 1 and calcination temperature of 500°C has the highest SCR activity with 98% NO conversion at 100°C using NH 3 reductant.…”

Comparison of physicochemical properties and selective catalytic reduction activities of CeMn/TiO2 catalysts with and without phosphorus additives

“…A manganese oxide (MnOx) SCR catalyst has been widely used for NOx removal because of its low cost, high thermal stability and higher SCR activity than other catalysts at low temperatures [7]. However, as MnOx loading amount increases agglomeration increases and MnOx is not dispersed perfectly on the catalyst surface [8]. Liu et al [8] found that Mn-Ni/OMA exhibits higher NOx conversion performance than Mn-Ni/γ-Al2O3 in the 90-240 °C temperature window.…”

“…However, as MnOx loading amount increases agglomeration increases and MnOx is not dispersed perfectly on the catalyst surface [8]. Liu et al [8] found that Mn-Ni/OMA exhibits higher NOx conversion performance than Mn-Ni/γ-Al2O3 in the 90-240 °C temperature window. Guo et al [9] revealed that Mn-Eu-Fe catalyst with Fe/Mn molar ratio of 1 and calcination temperature of 500 °C has the highest SCR activity with 98% NO conversion at 100 °C using NH3 reductant.…”