# Energy‐Efficient, Sustainable Cascade Glucose Electrooxidation into Glucaric Acid

## TL;DR

This paper introduces an energy-efficient system to convert glucose into glucaric acid, a key chemical, using a two-step process that also generates electricity, making the process more sustainable.

## Contribution

The study introduces a novel tandem electrooxidation system that improves energy efficiency and product yield in glucaric acid production.

## Key findings

- The tandem system achieves 91.8% Faradaic efficiency and nearly 100% conversion efficiency for glucose to gluconic acid.
- The system improves overall energy efficiency from 13.8% to 31.8% compared to conventional methods.
- The system generates electricity of 1.24 × 10⁵ kWh per kiloton of glucaric acid produced.

## Abstract

Glucaric acid (GRA) is a critical platform chemical for manufacturing biodegradable materials. Selective glucose (GLU) electrooxidation into GRA provides a sustainable route for biomass valorization. However, conventional methods suffer from energy‐intensive processes due to excessive operational potential exceeding 1.2 V. Here we demonstrate an energy‐efficient tandem system that decouples GRA electrosynthesis into cascade GLU‐to‐gluconic acid (GNA) and GNA‐to‐GRA oxidation. When pairing an Au/C catalyst for selective aldehyde oxidation and an AuPt/C catalyst for hydroxyl oxidation, we achieve 91.8% Faradaic efficiency and nearly 100% conversion efficiency at 0.6 VRHE for GLU‐to‐GNA oxidation, and 81% Faradaic efficiency and 90% conversion efficiency at 0.55 VRHE for GNA‐to‐GRA oxidation. Chronoamperometry demonstrates ∼100% substrate conversion with a minor decrease in product selectivity, confirming the catalyst's excellent stability. Our tandem system improves the overall GLU‐to‐GRA energy efficiency from 13.8% for conventional one‐step route to 31.8%. When oxygen reduction is selected as paired reaction, our system not only enables efficient chemical electrosynthesis, but is also estimated to generate electricity of 1.24 × 105 kWh per kiloton GRA, outperforming traditional method with energy consumption of 4.31 × 105 kWh. Our work establishes a sustainable and economically viable pathway for biomass valorization, offering a blueprint for circular, carbon‐neutral chemical production.

This study presents a tandem system that efficiently converts glucose into glucaric acid while generating renewable electricity. By decoupling the oxidation process into two cascaded steps, the system achieves an overall 90% Faradaic efficiency and 80% conversion efficiency at ∼0.6 VRHE, significantly reducing energy consumption compared to traditional one‐step routes at >1.2 VRHE.