A MoO₃–Metal–Organic Framework Composite as a Simultaneous Photocatalyst and Catalyst in the PODS Process of Light Oil

Abstract

Photo-oxidative desulfurization (PODS) properties of MoO3–metal–organic framework composite photocatalysts were investigated by introducing the proper weight percent of MoO3 into a Zn­(II)-based MOF, [Zn­(oba)­(4-bpdh)0.5] n ·1.5DMF (TMU-5), for the mineralization of dibenzothiophene from model oil. The addition of 3 wt % of MoO3 into a TMU-5 host acting as a crystal growth inhibitor was confirmed by PXRD and BET results. For the first time, under mild and green reaction conditions, 5 wt % MoO3–TMU-5 composite (MT-5) exhibited good photocatalytic activity in the model oil PODS reaction, which has no limitations in the current oxidative desulfurization catalytic systems. Only 3% of the total amount of MoO3 content in the MT catalyst is leached during the reaction. In addition, the rate of PODS of MT-5 obeys a pseudo-first-order equation with an apparent rate constant of 0.0305 min–1 and half-life t 1/2 of 22.7 min. Radical scavenger experiments and terephthalic acid fluorescence techniques confirmed that OH • and O2 •– are the main reactive species in the dibenzothiophene photocatalytic degradation. The synergic effects of the active surface of TMU-5 (organic linkers as antennas) together with the active sites of MoO3 may lead to the further enhancement of the PODS activity of the MT-5 photocatalyst. Moreover, a possible photocatalytic desulfurization mechanism was proposed in the presence of MoO3–TMU-5 composites.

Confined Heteropoly Blues in Defected Zr‐MOF (Bottle Around Ship) for High‐Efficiency Oxidative Desulfurization

“…FT‐IR spectra of pure PMA show four characteristic bands at 1055 cm −1 (P‐O a ), 958 cm −1 (MoO d , terminal oxygen), 866 cm −1 (MoO b Mo, bridging oxygen), and 786 cm −1 (MoO c Mo bridging oxygen) attributed to PMo 12 O 40 3− Keggin anion according to the literature. [ 6 ] The IR spectra of [Bmim] 3 PMo 12 O 40 clearly show characteristic bands assigned to Bmim cation (1168, 1458, and 1570 cm −1 ) [ 45 ] together with PMo 12 O 40 3− Keggin anion. 1168 and 1570 cm −1 are assigned to imidazole HCC and HCN bending, and imidazole ring stretching, respectively.…”

Metal–Organic Frameworks Encapsulating Active Nanoparticles as Emerging Composites for Catalysis: Recent Progress and Perspectives

“…Different from traditional photocatalysts, MOFs show some distinct photocatalytic properties arising from metal node, organic linker or both . To effectively separate electron and hole generated by light irradiation and improve the catalytic efficiency, MOFs are promising hosts for encapsulating electron acceptors and semiconductive NPs, such as metals, metal oxides, POMs, photoactive metal complexes or dyes, in which they will generate intriguing synergy functions compared with single counterparts.…”

Metal‐Organic Framework‐Based Catalysts for Oxidative Desulfurization

“…A robust porous 3D material based on Zn (II) 4,4‐oxybisbenzoic acid) and 2,5‐bis(4‐pyridyl)‐3,4‐diaza‐2,4‐hexadiene (TMU‐5) has been reported and used as host for the photoactive MoO 3 . The obtained material was used for the aerobic photooxidation of DBT under UV‐light, resulting in over 95 % of efficiency and satisfactory recyclability …”