The recent advances of organic synthesis reactions based on heterogeneous visible-light photocatalysis are reviewed.

Ethylbenzene is the major side product in benzene alkylation with methanol and it is difficult to be suppressed over hierarchical porous ZSM-5. Moreover, the separation of ethylbenzene from xylene still remains a great challenge. Our research indicated that ethylbenzene formation could be highly suppressed by changing the Si/Al ratio of the catalyst. Hierarchical porous ZSM-5 catalysts with different Si/Al ratios were prepared via reducing the amount of Al in the solvent evaporation assisted dry gel conversion method. In this method, tetra-n-propylammonium hydroxide was used as the direct agent to create micropores, and hexadecyltrimethoxysilane was added to create additional porosities by forming organic assemblies which occupied a certain space between zeolitic walls. The catalyst with a Si/Al ratio of 1800 could achieve high benzene conversion (59.5%) and high xylene selectivity (39.0%) as well as excellent suppression of ethylbenzene formation (<0.1%).

Using high-valent Au(III) catalysis is highly desirable in many reactions; however, it is plagued by the poor stability of Au(III) complexes. Still, conventional catalysts need high Au content makes the high price and demand for Au is one of the major obstacles limiting their large-scale application. Here we demonstrate that stable and catalytically active Au(III) complexes can be obtained using Supported Ionic Liquid Phase (SILP) technology. The resulting heterogeneous Au–IL/AC catalysts combine the advantages of the catalytic species being stabilised in the Au(III) form by forming a Au(III)–IL complex and the need for a less expensive metal catalyst because the active component can be better developed in a homogeneous reaction medium. When used in acetylene hydrochlorination reaction, this catalyst displayed an excellent specific activity and superior long-term stability. Under the same reaction conditions, the Au(III)–IL/AC catalyst shows higher activity and stability towards the vinyl chloride monomer (VCM) than IL-free Au/AC (C₂H₂ conversion = 72.1% at 180 °C compared to 16.1% without IL). It also delivered stable performance within the conversion of acetylene, reaching more than 99.4%, and there was only a 3.7% C₂H₂ conversion loss after running for 300 h under the reaction conditions of a temperature of 180 °C and a C₂H₂ hourly space velocity of 30 h⁻¹. Its exceptional ability to maintain the high activity and stability further demonstrated the potential for the replacement of Hg-based catalysts for acetylene hydrochlorination.

The hydrogenation of phenol to cyclohexanol under mild conditions (∼340 K) was achieved over Raney Ni catalyst in the aqueous phase. The adsorption–desorption properties of the reactants (phenol and H₂) and the products (cyclohexanone and cyclohexanol) on the Raney Ni catalyst are different in the aqueous phase and the organic phase. The hydrogenation rate of phenol is improved because the Raney Ni catalyst adsorbs more H₂ and phenol in water than in methanol. Meanwhile, the higher uptakes of H₂ and the lower desorption rates for cyclohexanone on the Raney Ni catalyst in the aqueous system result in the further hydrogenation of cyclohexanone to cyclohexanol.

Cu–CeO₂/AC catalysts exhibited the highest n-butanol yields (21.6% and nearly 20%) under mild reaction conditions in batch and fixed-bed reactors, respectively, which could be ascribed to the synergy of Cu, CeO₂ and the activated carbon support.