Cu2O Photocatalyst for Solar CO2 Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for reducing CO2 emissions, such as electroreduction, hydrogenation, and photocatalysis using TiO2, are inefficient, costly, or limited by the need for electricity and UV light absorption, which does not utilize the full solar spectrum effectively.

Innovation Solution

Converting CO2 to methanol or CO by irradiating CO2, water, and Cu2O with specific (i i 0) facets, where i is 1 to 12, using visible light, and optionally adsorbing MoS2 onto Cu2O, to facilitate efficient photocatalytic conversion without electricity input, utilizing abundant elements and maximizing solar energy absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If TiO2 photocatalysis is used for CO2 reduction, then the process can proceed without electricity input, but the light absorption is limited exclusively to UV light which composes only 5% of the solar spectrum

Engineering Contradiction:

Improvelight absorption efficiencyVSAvoidsolar spectrum utilization

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent changes the material parameter from TiO2 to Cu2O, which fundamentally alters the optical properties. Cu2O has a bandgap of approximately 2.0 eV, enabling it to absorb visible light with wavelengths up to 620 nm, thereby expanding the usable solar spectrum from 5% (UV only) to approximately 45% (visible light range).

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures where Cu2O is combined with co-catalysts such as MoS2, Pt, or Pd. These composites enhance the photocatalytic activity by improving charge separation and providing additional active sites for CO2 reduction, while maintaining broad visible light absorption capability.

Inventive Principle:

Principle #40Composite materials

2Productivity

If electroreduction is used for CO2 reduction, then the conversion process can be controlled, but it requires a large overpotential and electrical energy input

Engineering Contradiction:

ImproveCO2 conversion efficiencyVSAvoidelectrical energy input

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the electrochemical reduction mechanism with a photocatalytic mechanism. Instead of using electrical energy to drive CO2 reduction through electrochemical reactions, the system uses photonic energy (visible light) to excite electrons in Cu2O, which then reduce CO2 through a photocatalytic pathway, eliminating the need for external electrical energy input.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The Cu2O photocatalyst absorbs visible light directly from the solar spectrum and uses this energy to drive the CO2 reduction reaction autonomously. The system is self-powered by sunlight, eliminating dependence on external electrical energy sources and reducing overall energy consumption.

Inventive Principle:

Principle #25Self-service

3Productivity

If hydrogenation of CO2 is used, then CO2 can be converted to fuels, but it involves the use of hydrogen which raises cost and safety issues

Engineering Contradiction:

Improvefuel production rateVSAvoidprocess safety and cost

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent introduces Cu2O as a photocatalytic intermediary that directly facilitates CO2 reduction using visible light. This replaces the hydrogenation pathway where H2 gas would be required. The Cu2O catalyst mediates the electron transfer from photogenerated carriers to CO2, enabling direct photocatalytic reduction without needing external hydrogen gas, thereby eliminating associated safety and cost issues.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Achieves high quantum efficiency and solar-to-fuel efficiency, providing a sustainable, low-cost, and stable method for CO2 reduction to methanol or CO, using Earth-abundant materials and producing oxygen as a byproduct, with Cu2O's visible light absorption enabling efficient solar energy conversion.

Implementation Method 1

irradiating CO2, water, and Cu2O having a (i i 0) facet to form methanol

Methodology Applied

Scientific EffectPhotocatalysis: Photosynthesis

Implementation Method 2

Cu2O's visible light absorption enabling efficient solar energy conversion

Methodology Applied

Scientific EffectVisible light absorption: Absorption (EM radiation)

Implementation Method 3

MoS2 adsorbed onto Cu2O

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 4

producing oxygen as a byproduct

Methodology Applied

Scientific EffectPhoto-oxidation: Photo-oxidation

Data Source

PatentUS10696614B2Photocatalytic reduction of carbon dioxide to methanol or carbon monoxide using cuprous oxide

Publication Date: 2020.06.30 UCHICAGO ARGONNE LLC

AI summary

Provided herein are methods of CO2 reduction to methanol or CO using a Cu2O catalyst.