Researchers look to new catalyst for eco-friendly route from sugar to glucaric acid
Back in 2004, the Department of Energy picked 12 biobased chemicals with the most commercial potential. Glucaric acid was fifth on the list.
Sugar-derived glucaric acid can serve as a renewable starting point for chemical intermediates with multi-million dollar markets, such as nylon’s precursor adipic acid. However, despite sprouting from renewable resources, the existing route to glucaric acid is far from green.
“The current process uses unfavorable reagents such as nitric acid and chlorine bleach, and it generates significant toxic byproducts,” said RV Chaudhari, CEBC Deputy Director and distinguished professor of chemical engineering at the University of Kansas.
Chaudhari’s team is searching for a safer route to glucaric acid. They hope to find a supported metal catalyst that can oxidize glucose using molecular oxygen in lieu of harmful mineral acids and bleaches. So far, the results are promising. By tagging platinum and copper metals onto a solid support, the researchers have synthesized a catalyst that can directly oxidize glucose to glucaric acid.
The next hurdle is to cut back on unwanted byproducts. Right now, glucaric acid makes up only a quarter of the final product yield. “While 25% selectivity is low, it is a big improvement over the three percent selectivity for other catalysts previously reported in the literature,” said Chaudhari.
Researchers have yet to test a slew of other ideas for improving catalyst performance. In the coming months they plan to tweak the structure of the catalyst, the metal composition and reaction conditions.
The good news is that the team is a step closer to discovering a cleaner, safer route for making a key biobased chemical.