Sword-like CuO/CeO₂ composites derived from a Ce-BTC metal–organic framework with superior CO oxidation performance

Abstract

Porous shape-controllable metal oxide composites derived from a metal–organic framework have gained more and more attention due to their extensive applications.

Kinetics of photocatalytic degradation of gaseous p‐xylene on UiO‐66‐NH2 and LaFeO3 thin films under combined illumination of ultraviolet and visible lights

“…Unlike the P25 catalyst, on UiO-66-NH 2 and LaFeO 3 catalysts, carbon dioxide inhibits the reaction, shown by the appearance of the term k 5 P CO2 in the denominator of Equation (22) and the value of constant k 5 is relatively high, ranked second after k 4 among the coefficients presenting in the denominator of the equation. This is caused by the dipole moment of CO 2 is 13.4 × 10 −40 C⋅m 2 .…”

“…On the P25 catalyst, the kinetics of the reaction irradiated by UV light are written in Equation (10), 58 similar to Equation (22). This means Equation (22) is the general kinetic equation for p-xylene photooxidation on MOF catalyst UiO-66-NH 2 and perovskite LaFeO 3 irradiated by combined UVvis lights as well as on P25 catalyst illuminated by UV light.…”

“…For all three catalysts, the value of exponent = 1 corresponds to the reaction occurring at high adsorbate coverages of the surface because of the small amount of catalyst used in the reaction (15 mg). The form of kinetic equations (22) shows that the substances involved in the reaction are adsorbed on the same type of active sites. However, the difference in the photochemical properties of the catalysts creates a difference in the value of the kinetic constants as well as the reaction order.…”

“…P25 and UiO-66-NH 2 catalysts weakly adsorb oxygen, so the value of coefficient k 3 in Equation (22) on both catalysts is very small or approximately equal to 0, so the term k 3 P O2 < < 1 and can be ignored from the denominator of Equation (22). Therefore, the dependence of the reaction rate versus the partial pressure of oxygen on these two catalysts is nearly linear, as seen in Figure 7 and in the work.…”

“…Owing to high specific surface area and pore volume, uniform pores, and chemical tenability, metal-organic frameworks (MOFs) have attracted attention in various fields, 14 especially in adsorption and separation of gas, [15][16][17] catalysis for VOCs removal, 18 and CO oxidation. [19][20][21][22][23] MOFs have been known as semiconductors due to its optical transition, electrochemical, and photochemical activity. 24,25 There are several researches using the MOF as a photocatalyst for the decomposition of organic compounds in the aqueous phase.…”