•The bimetallic Cu-Ce-SAPO-34 monolith catalyst was firstly prepared.•The interaction between Ce and Cu could improve the dispersion of copper species and increase the amount of isolated Cu2+ ions.•The addition of Ce could promote the redistribution of CuO particles.•The addition of Ce could inhibit the degradation of acid density during hydrothermal treatment.•The introduction of Ce could obviously improve the hydrothermal stability of Cu-SAPO-34.The activity and hydrothermal stability of Cu-SAPO-34 and CuCe-SAPO-34 for selective catalytic reduction of NOx with ammonia (NH3-SCR) were investigated systematically. The catalysts were prepared by wet-impregnation method, and characterized by N2 adsorption, X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS), Ultraviolet-visible diffuse reflectance spectrum (UV–vis-DRS), H2-temperature programmed reduction (H2-TPR) and NH3-temperature programmed desorption (NH3-TPD). The experimental results of fresh catalysts suggested that Ce mainly existed on the surface of the catalyst and was well dispersed in the form of Ce3+, and its interaction with copper could improve the dispersion of copper species and increase the amount of isolated Cu2+ ions, so that CuCe-SAPO-34 performed better NH3-SCR activity than Cu-SAPO-34. After hydrothermal aging at 800 °C for 12 h, the characterization results indicated that the introduction of cerium effectively improved the textural and structural stability of SAPO-34 since more cations at the exchange site of SAPO-34 could decrease the concentration of SiO(H)Al bond which was closely related to the damage of the SAPO-34 framework. Moreover, the addition of Ce could prevent the decrease of acid densities, promote the redistribution of CuO during hydrothermal aging and provide higher amount of isolated Cu2+ ions, leading to superior hydrothermal stability of CuCe-SAPO-34 catalyst.The CuCe-SAPO-34 performed superior NH3-SCR activity and hydrothermal stability than the Cu-SAPO-34 catalyst.

The over-consumption of fossil fuels resulted in the large quantity emission of carbon dioxide (CO2), which was the main reason for the climate change and more extreme weathers. Hence, it is extremely pressing to explore efficient and sustainable approaches for the carbon-neutral pathway of CO2 utilization and recycling. In our recent works with this context, we developed successfully a novel “chemical vapor deposition integrated process (CVD-IP)” technology to converting robustly CO2 into the value-added solid-form carbon materials. The monometallic FeNi0–Al2O3 (FNi0) and bimetallic FeNix–Al2O3 (FNi2, FNi4, FNi8 and FNi20) samples were synthesized and effective for this new approach. The catalyst labeled FNi8 gave the better performance, exhibited the single pass solid carbon yield of 30%. These results illustrated alternative promising cases for the CO2 capture utilization storage (CCUS), by means of the CO2 catalytic conversion into the solid-form nano carbon materials.Download high-res image (222KB)Download full-size imageThe bimetallic FeNix–Al2O3 (FNi2, FNi4, FNi8 and FNi20) samples were synthesized and effective for CO2 catalytic conversion into the solid-form nano carbon materials with good efficiency.

MnOx/CeO2–ZrO2–Al2O3 (MnOx/CZA) catalysts with different amounts of manganese loading were prepared by incipient wetness impregnation method for selective catalytic reduction (SCR) of NO with NH3 at low temperature. The catalysts were characterized by N2 adsorption–desorption measurement, XRD, XPS, and H2-TPR. Catalytic activity tests reveal that the MnOx/CZA catalyst with 10% manganese loading has the best catalytic activity, almost 90% NO is translated to N2 in the temperature range of 143–300 °C. The highly dispersed MnOx species, the good oxidation activity of NO to NO2, the existent synergistic effect between the manganese and cerium oxides, and the various oxidation states of manganese oxides may be the main reasons for the best SCR activity. In addition, the SCR activity is slightly influenced in the presence of SO2 and H2O, while such effect is restorable after heating treatment.Graphical abstractThe selective catalytic reduction of NO by NH3 over MnOx/CeO2–ZrO2–Al2O3 catalysts with different manganese loadings was studied. The NO conversion increased with the increasing of manganese content until the amount of manganese reached 10%. After this level, the SCR activity slightly decreased with the increase of manganese loading.Download high-res image (128KB)Download full-size imageHighlights► MnOx/CeO2–ZrO2–Al2O3 catalysts have excellent performance for SCR of NO by NH3 at low temperature. ► The 10% MnOx/CeO2–ZrO2–Al2O3 is resistant to H2O and SO2. ► The 10% MnOx/CeO2–ZrO2–Al2O3 has good oxidation activity of NO to NO2. ► The manganese oxide exists as highly dispersed MnOx species on the surface of 10% MnOx/CeO2–ZrO2–Al2O3. ► The manganese oxides species exist as various oxidation states in 10% MnOx/CeO2–ZrO2–Al2O3.