铂不适合用来制作燃料电池
文章来源:未知 文章作者:enread 发布时间:2012-07-13 06:07 字体: [ ]  进入论坛
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Fuel cells are inefficient1 because the catalyst2 most commonly used to convert chemical energy to electricity is made of the wrong material, a researcher at Case Western Reserve University argues. Rather than continue the futile3 effort to tweak that material -- platinum4 -- to make it work better, Chemistry Professor Alfred Anderson urges his colleagues to start anew. "Using platinum is like putting a resistor in the system," he said. Anderson freely acknowledges he doesn't know what the right material is, but he's confident that researchers' energy would be better spent seeking it out than persisting with platinum.

"If we can find a catalyst that will do this [more efficiently]," he said, "it would reach closer to the limiting potential and get more energy out of the fuel cell."

Anderson's analysis as well as a guide for a better catalyst have been published in a recent issue of Physical Chemistry Chemical Physics and in Electrocatalysis online.

Even in the best of circumstances, Anderson explains, the chemical reaction that produces energy in a fuel cell like those being tested by some car companies ends up wasting a quarter of the energy that could be transformed into electricity. This point is well-recognized in the scientific community, but to date efforts to address the problem have proved fruitless.

Anderson blames the failure on a fundamental misconception as to the reason for the energy waste. The most widely accepted theory says that impurities6(杂志) are binding7 to the platinum surface of the cathode(阴极) and blocking the desired reaction.

"The decades-old surface-poisoning explanation is lame5, because there is more to the story" Anderson said.

To understand the loss of energy, he used data derived8 from oxygen-reduction experiments to calculate the optimal9 bonding strengths between platinum and intermediate(中间的) molecules10 formed during the oxygen-reduction reaction. The reaction takes place at the platinum-coated cathode.

He found the intermediate molecules bond too tightly or too loosely to the cathode surface, slowing the reaction and causing a drop in voltage. The result is the fuel cell produces about .93 volts11 instead of the potential maximum of 1.23 volts.

To eliminate the loss, calculations show, the catalyst should have bonding strengths tailored so that all reactions taking place during oxygen reduction occur at or as near to 1.23 volts as possible.

Anderson said the use of volcano plots, which are a statistical12 tool for comparing catalysts13, has actually misguided the search for the best one "They allow you to grade a series of similar catalysts, but they don't point to better catalysts."

He said a catalyst made of copper14 laccase(漆酶) , a material found in trees and fungi15, has the desired bonding strength but lacks stability. Finding a catalyst that has both is the challenge.

Anderson is working with other researchers exploring alternative catalysts as well as an alternative reaction pathway in an effort to increase efficiency.



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1 inefficient c76xm     
adj.效率低的,无效的
参考例句:
  • The inefficient operation cost the firm a lot of money.低效率的运作使该公司损失了许多钱。
  • Their communication systems are inefficient in the extreme.他们的通讯系统效率非常差。
2 catalyst vOVzu     
n.催化剂,造成变化的人或事
参考例句:
  • A catalyst is a substance which speeds up a chemical reaction.催化剂是一种能加速化学反应的物质。
  • The workers'demand for better conditions was a catalyst for social change.工人们要求改善工作条件促进了社会变革。
3 futile vfTz2     
adj.无效的,无用的,无希望的
参考例句:
  • They were killed,to the last man,in a futile attack.因为进攻失败,他们全部被杀,无一幸免。
  • Their efforts to revive him were futile.他们对他抢救无效。
4 platinum CuOyC     
n.白金
参考例句:
  • I'll give her a platinum ring.我打算送给她一枚白金戒指。
  • Platinum exceeds gold in value.白金的价值高于黄金。
5 lame r9gzj     
adj.跛的,(辩解、论据等)无说服力的
参考例句:
  • The lame man needs a stick when he walks.那跛脚男子走路时需借助拐棍。
  • I don't believe his story.It'sounds a bit lame.我不信他讲的那一套。他的话听起来有些靠不住。
6 impurities 2626a6dbfe6f229f6e1c36f702812675     
不纯( impurity的名词复数 ); 不洁; 淫秽; 杂质
参考例句:
  • A filter will remove most impurities found in water. 过滤器会滤掉水中的大部分杂质。
  • Oil is refined to remove naturally occurring impurities. 油经过提炼去除天然存在的杂质。
7 binding 2yEzWb     
有约束力的,有效的,应遵守的
参考例句:
  • The contract was not signed and has no binding force. 合同没有签署因而没有约束力。
  • Both sides have agreed that the arbitration will be binding. 双方都赞同仲裁具有约束力。
8 derived 6cddb7353e699051a384686b6b3ff1e2     
vi.起源;由来;衍生;导出v.得到( derive的过去式和过去分词 );(从…中)得到获得;源于;(从…中)提取
参考例句:
  • Many English words are derived from Latin and Greek. 英语很多词源出于拉丁文和希腊文。 来自《简明英汉词典》
  • He derived his enthusiasm for literature from his father. 他对文学的爱好是受他父亲的影响。 来自《简明英汉词典》
9 optimal zmDzhM     
adj.最适宜的;最理想的;最令人满意的
参考例句:
  • What is the optimal mix of private and public property rights in natural resources?私人和国家的自然资源产权的最适宜的组合是什么?
  • Optimal path planning is a key link for the sailing contest.帆船最优行驶路径规划是帆船比赛取胜的关键环节。
10 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
参考例句:
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
11 volts 98e8d837b26722c4cf6887fd4ebf60e8     
n.(电压单位)伏特( volt的名词复数 )
参考例句:
  • The floating potential, Vf is usually only a few volts below ground. 浮置电势Vf通常只低于接地电位几伏。 来自辞典例句
  • If gamma particles are present, potential differences of several thousand volts can be generated. 如果存在γ粒子,可能产生几千伏的电位差。 来自辞典例句
12 statistical bu3wa     
adj.统计的,统计学的
参考例句:
  • He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
  • They're making detailed statistical analysis.他们正在做具体的统计分析。
13 catalysts 677fdea123458fc2ff92eb84d07254e9     
n.催化剂( catalyst的名词复数 );触媒;促进因素;有感染力的人
参考例句:
  • The first catalytic converters were called conventional oxidation catalysts. 最初的转化器叫做常规氧化催化器。 来自辞典例句
  • Many processes that are essential to the chemical industry use heterogeneous catalysts. 很多重要的化学工业过程就是使用多相催化剂的。 来自辞典例句
14 copper HZXyU     
n.铜;铜币;铜器;adj.铜(制)的;(紫)铜色的
参考例句:
  • The students are asked to prove the purity of copper.要求学生们检验铜的纯度。
  • Copper is a good medium for the conduction of heat and electricity.铜是热和电的良导体。
15 fungi 6hRx6     
n.真菌,霉菌
参考例句:
  • Students practice to apply the study of genetics to multicellular plants and fungi.学生们练习把基因学应用到多细胞植物和真菌中。
  • The lawn was covered with fungi.草地上到处都是蘑菇。
TAG标签: cells fuel electricity
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