Hydrogen is known as the next generation of clean energy, but its storage and transportation has been a bottleneck that hinders the large-scale application of hydrogen fuel. In particular, hydrogen fuel cells are promising alternative powers supplies for a range of vehicle and portable energy applications, with in-situ release of the required hydrogen fuel from a stable liquid offering one way to ensuring its safe storage and transportation. At present, Toyota's commercial fuel cell vehicle, Mirai, uses hydrogen compressed to 690 times atmospheric pressure in a 120L tank, which possess a potential safety issue. In addition, the infrastructure for hydrogen fueling station remains challenging inside city areas. In view of these challenges, one possible solution is to store hydrogen in liquid methanol and produce hydrogen in-situ by the liquid phase reforming reaction of water and methanol to power the fuel cells.
In a recent study, Wu Zhou, a professor at the School of Physical Sciences and CAS Key Laboratory of Vacuum Sciences, University of Chinese Academy of Sciences (UCAS), has joined the effort with a few groups from Peking University (Prof. Ding Ma), Institute of Coal Chemistry CAS (Prof. Xiao-Dong Wen), and Dalian University of Technology (Prof. Chuan Shi), to develop a new catalyst that produces hydrogen from methanol and water at low temperature of 150-190˚C, which traditional approaches do at 200-350˚C. Using atomic resolution electron microscopy, the team discovered a strong interaction between platinum (Pt) and molybdenum carbide (MoC), which leads to atomically dispersed platinum on molybdenum carbide and forms a high density of catalytically active centers. The Pt atoms can effectively activate the methanol, while molybdenum carbide makes water molecules more reactive. The synergistic effect between the two brings unprecedented catalytic activity for hydrogen formation from water and methanol, nearly two orders of magnitude better than traditional platinum-based catalysts. The team estimates that a 50L tank of methanol and catalysts containing only 6 grams of platinum should produce enough hydrogen to power a fuel cell concept vehicle travelling for about 690 km, bringing the fuel cost down to ~$2 per 100 km.
The study, published as “Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts” on Nature, is available online:
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature21672.html
This research was supported in part by the University of Chinese Academy of Sciences.
Figure 1. Hydrogen production from water and methanol using a platinum-molybdenum carbide catalyst.
Figure 2. Electron microscopy image of atomically dispersed Pt-MoC catalyst and theoretical results showing the charge-density map at the catalytically active sites.
