This review provides recent advances in the conversion of CO2 to methanol, methanol to hydrocarbons, and direct conversion of CO2 to hydrocarbons via methanol intermediate over various monofunctional and bifunctional solid catalysts.

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A series of Sn‐SBA‐15 catalysts were synthesized using a post‐synthetic metal implantation method for converting carbohydrates to methyl lactate. The tin species were highly dispersed and isolatedly grafted in the framework of SBA‐15 under the tin salt concentration between 2 and 25 wt%. They solely provided a large number of Lewis acid sites, which showed robust activity for carbohydrates conversion in contrast to the performance of tin dioxide domains or particles. Over a Sn‐SBA‐15 catalyst (Si/Sn molar=150), the Lewis acid density was 45.9 μmol/g, and methyl lactate yield reached a high value of 57.0 % from inulin conversion in methanol at 433 K for 20 h, without the formation of methyl levulinate by‐product. The Sn‐SBA‐15 catalysts were rather stable under reaction conditions, and cycled at least for 4 times without deactivation.

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Ball milling pretreatment was found to be an efficient method to promote the catalytic conversion of lignocellulosic biomass to ethylene glycol (EG). After 3–6 h ball milling of Miscanthus at 450 rpm, the EG yield reached about 52%, which is comparable to the result of pure cellulose conversion. The reasons of the promotion effect were investigated by characterizing the structure of biomass and the reaction residuals with X-ray diffraction, scanning electron microscopy, particle size distribution analyzer, contact angle measurement, thermogravimetric analysis-differential scanning calorimetry, and Fourier-transform infrared spectroscopy. The mild ball milling liberated (hemi)­cellulose from the compact plant tissues without affecting the crystallinity of cellulose. It reduced the size of biomass to 30 μm and improved the accessibility of (hemi)­cellulose, leading to a hydrophilic surface and high energy state of biomass for catalytic conversion. During the catalytic conversion, the mass transfer between sugar intermediates and heterogeneous hydrogenation catalysts were improved. Correspondingly, the self-reaction of sugar intermediates, and the reactions between sugar intermediates and lignin fractions were suppressed, resulting in the high EG yield.

Ethylene glycol (EG), synthesized from biomass, frequently contains refractory 1,2‐propanediol (PDO) and 1,2‐butanediol (BDO). Selective removal of PDO and BDO was realized herein by catalytic dehydration to form volatile aldehydes, ketones, and acetals. Various acidic and basic catalysts were screened under a range of conditions for the conversion of a mixture containing 73 wt % EG, 20 wt % PDO, and 7 wt % BDO. Over H‐Beta 26 zeolite, the most selective catalyst among tested, PDO and BDO conversions reached 99.1 and 99.3%, respectively, after 4 h reaction at 453 K, with separation factors over 2. The activation energies for EG, PDO, and BDO dehydration were ca. 99.3, 69.9, and 54.0 kJ/mol, respectively, accounting for the high reactivity of PDO and BDO. The dehydration largely proceeded in the micropores of H‐Beta and depended on the number of strong Brønsted acid sites, but excessively strong acid sites enhanced the polymerization of EG. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4032–4042, 2017

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The use of Fe-Zn double-metal cyanide as a solid catalyst for synthesizing biodegradable, hyperbranched polymers from diacids and glycerol has been reported, for the first time, wherein acidity, micro-mesoporosity and hydrophobicity of the catalyst played an important role in controlling gelation.