Conventional production of methanol is very inefficient since only 10%-15% one-pass conversion is achieved typically at 5.0-10.0 MPa and 523-573 K due to the severe thermodynamic limitations of its exothermal reaction (CO + 2H2 = CH3OH). A novel route of low-temperature methanol synthesis developed by Tsubaki et al from CO2-containing syngas only by adding alcohols including methanol itself is reviewed. These alcohols act as the homogeneous co-catalysts and solvent

realizing 70%-100% one-pass conversion at only 5.0 MPa and 443 K. The key step is the reaction of the adsorbed formate species with alcohols to yield ester species at low temperatures

followed by the hydrogenation of ester by hydrogen atoms on metallic Cu. This changes the normal reaction path of conventional

high-temperature methanol synthesis from formate via methoxy to methanol. A series of new methods

such as sol-gel auto-combustion

solid-state combustion and formic acid assisted combustion methods

to prepare highly active metallic Cu/ZnO catalysts without further reduction are also reviewed. During the decomposition of metal-contained precursors in an argon atmosphere

H2 and CO are liberated and act in situ as the reducing agents to obtain pure metals and metallic catalysts. The X-ray diffraction

X-ray photoelectron spectroscopy

energy dispersive spectroscopy

and temperature-programmed reduction analysis reveal that the as-prepared catalyst without further reduction is converted into metallic Cu0 and ZnO species.