Bimetallic catalytic systems Fe–Me (Pt, Pd, Cu) demonstrate synergy in the activity/selectivity pattern in reactions involving hydrogen: selective hydrogenation of CC bonds, NO₂ and carbonyl groups and hydrogenolysis of C–O bonds.

The development and research of highly effective heterogeneous catalysts for the hydrogenation of esters, providing high activity and selectivity of the formation of the corresponding alcohols, is an urgent task of modern heterogeneous catalysis.

Currently, microwave radiation is widely used in various chemical processes in order to intensify them and carry out processes within the framework of “green” chemistry approaches. In the last 10 years, there has been a significant increase in the number of scientific publications on the application of microwaves in catalytic reactions and synthesis of nanomaterials. It is known that heterogeneous catalysts obtained under microwave activation conditions have many advantages, such as improved catalytic characteristics and stability, and the synthesis of nanomaterials is accelerated several times compared to traditional methods used to produce catalysts. The present review article is to summarize the results of modern research on the use of microwave radiation for the synthesis of heterogeneous catalytic nanomaterials and discusses the prospects for research in the field of microwave-induced liquid-phase heterogeneous catalysis in hydrogenation.

Supported bimetallic Fe–Cu/SiO₂ materials are synthesized, and their catalytic activity in hydrogenation of dinitrobenzene to phenylenediamine at 145–180°С and 1.3 MPa hydrogen pressure is studied for the first time. The best results (89% selectivity toward _p-phenylenediamine at complete conversion of _p-dinitrobenzene) are obtained for the sample synthesized via co-deposition with subsequent calcination at 300°С. The sample contains 7% iron and 3% copper. The formation of separate phases of metal oxides (for the catalysts prepared by impregnation) and mixed bimetallic oxide phases (in case of co-deposition procedure) in calcined samples is revealed via thermoprogrammed reduction with hydrogen.

For the first time, the new microwave-assisted method for the synthesis of copper phyllosilicates on a commercial SiO₂ carrier was developed. The application of microwave synthesis allowed to decrease the synthesis time from 9 to 6 h compared to the traditional DPU method of preparing chrysocolla. The synthesized catalysts were studied by N₂ adsorption, TEM and XRD methods. Catalysts prepared by microwave method are highly effective in the selective hydrogenation of the С≡С bond in 1,4-butynediol to 1,4-butenediol and 2-phenylethinylaniline with a selectivity of 96.5% and 100% at full conversion for 2 and 0.5 h of the reaction, respectively.

Hydrolytic lignin is one of the non-demanded carbon materials. Its CO₂-assisted conversion is an important way to utilize it. The use of the catalysts prepared by metal deposition on the surface of hydrolytic lignin makes it possible to apply milder conditions of the conversion process with CO₂ and to improve the economic indicators. The development of methods of deposition of the active phase is a problem of high importance for any heterogeneous catalytic processes. This work aimed at investigating the influence of the conditions of iron deposition on the surface of hydrolytic lignin on the process of CO₂-assisted conversion of lignin. Different Fe precursors (Fe(NO₃)₃, FeSO₄, Fe₂(SO₄)₃), solvents (water, isopropanol, acetone, and ethanol), and concentrations of the solution were used; the properties of Fe/lignin composites were estimated by SEM, EDX, TEM, XRD methods and catalytic tests. All the prepared samples demonstrate a higher conversion compared to starting lignin itself in the carbon dioxide-assisted conversion process. The carbon dioxide conversion was up to 66% at 800 °C for the sample prepared from Fe(NO₃)₃ using a twofold water volume compared to incipient wetness water volume as a solvent (vs. 39% for pure lignin).