A Direct Strategy for Producing Carbon-Nanotube-Based Electrocatalytic Electrodes

Introduction

Fabrication of pre-existing carbonaceous electrode materials for electrocatalysis is inherently difficult to control, since it involves a multi-step process and requires surface activation, chemical modification or heat treatment, and/or other processing steps. Additionally, the loading of noble metal-based catalysts generally occurs as a secondary step either by physical, chemical, or electrochemical deposition methods.

Invention Description

The method proposed avoids the problems encountered when using pre-existing materials by preparing the electrodes directly by chemical vapor deposition (CVD) using metal precursors containing both carbon and heteroatom sources, in addition to a carbon growth catalyst to fabricate carbon nanotube electrodes with incorporated electrocatalyst.

Benefits

• Direct and low-cost methodology
• No post-processing, post-treatment, post-activation, or post-chemical modification
• Heteroatom-doped carbon is inherently catalytic

Features

• Direct growth of aligned, high surface area multi-walled carbon nanotubes on conductive substrates
• Simultaneous loading or dispersion of electrocatalytic components via chemical vapor deposition (CVD) of metal-containing or other heteroatom-containing precursor(s)
• Formation of mesoporous, high surface area, 3-D electrode geometries of oriented carbon nanotubes for increased mass transport
• Demonstrated excellent electrocatalytic ability for the reduction of dioxygen and the decomposition of hydrogen peroxide
• Carbon nanotube-based electrodes and electrocatalyst are prepared simultaneously

Market Potential/Applications

U.S. battery market is estimated to be at $10.4B (Freedonia, 2002). Carbon electrode demand is expected to be 700kMT in 2003, growing to 725kMT in 2004 (International Iron and Steel Institute SGL Carbon Group, 2002). The market for carbon nanotube materials was $8M in 2002 and is expected to reach over $230M in the next few years (Business Communications Corp., Chemical Engineering 2/2003). The fuel-cell market expects to sell 3 million units in 2008, 50 million units in 2010, and 200 million units in 2011 (Allied Business Intelligence, IEEE Spectrum, 6/2003). The market for fuel cells could reach $20B by 2010 (Principia Partners, 10/2002). The gas sensors market is expected to exceed $2.5B by 2010 (Nanomaterials Research, LLC, 2002).

Applications: Electroanalytical sensors, air batteries, fuel cells, gas diffusion electrodes

IP Status

One PCT Application filed

UT Researcher

• Keith Stevenson, Ph.D., Department of Chemistry and Biochemistry, The University of Texas at Austin
  
• Stephen Maldonado, Department of Chemistry and Biochemistry, The University of Texas at Austin

Contact:

University os texas,
Austin, USA
Website : www.otc.utexas.edu