catalyst

11 Articles

A Fascinating Plot Twist As Researchers Recreate Classic “Primordial Soup” Experiment

October 31, 2021 by 46 Comments

Science is built on reproducibility; if someone else can replicate your results, chances are pretty good that you’re looking at the truth. And there’s no statute of limitations on reproducibility; even experiments from 70 years ago are fair game for a fresh look. A great example is this recent reboot of the 1952 Miller-Urey “primordial soup” experiment which ended up with some fascinating results.

At the heart of the Miller-Urey experiment was a classic chicken-and-the-egg paradox: complex organic molecules like amino acids and nucleic acids are the necessary building blocks of life, but how did they arise on Earth before there was life? To answer that, Stanley Miller, who in 1952 was a graduate student of Harold Urey,  devised an experiment to see if complex molecules could be formed from simpler substances under conditions assumed to have been present early in the planet’s life. Miller assembled a complicated glass apparatus, filled it with water vapor and gasses such as ammonia, hydrogen, and methane, and zapped it with an electric arc to simulate lightning. He found that a rich broth of amino acids accumulated in the reaction vessel; when analyzed, the sludge was found to contain five of the 20 amino acids.

The Miller-Urey experiment has been repeated over and over again with similar results, but a recent reboot took a different tack and looked at how the laboratory apparatus itself may have influenced the results. Joaquin Criado-Reyes and colleagues found that when run in a Teflon flask, the experiment produced far fewer organic compounds. Interestingly, adding chips of borosilicate glass to the Teflon reaction chamber restored the richness of the resulting broth, suggesting that the silicates in the glassware may have played a catalytic role in creating the organic soup. They also hypothesize that the highly alkaline reaction conditions could create microscopic pits in the walls of the glassware, which would serve as reaction centers to speed up the formation of organics.

This is a great example of a finding that seems to knock a hole in a theory but actually ends up supporting it. On the face of it, one could argue that Miller and Urey were wrong since they only produced organics thanks to contamination from their glassware. And it appears to be true that silicates are necessary for the abiotic generation of organic molecules. But if there was one thing that the early Earth was rich in, it was silicates, in the form of clay, silt, sand, rocks, and dust. So this experiment lends support to the abiotic origin of organic molecules on Earth, and perhaps on other rocky worlds as well.

[Featured image credit: Roger Ressmeyer/CORBIS, via Science History Institute]

Common Chemicals Combine To Make Metallic Sodium

February 26, 2019 by 16 Comments

There’s no debating that metallic sodium is exciting stuff, but getting your hands on some can be problematic, what with the need to ship it in a mineral oil bath to keep it from exploding. So why not make your own? No problem, just pass a few thousand amps of current through an 800° pot of molten table salt. Easy as pie.

Thankfully, there’s now a more approachable method courtesy of this clever chemical hack that makes metallic sodium in quantity without using electrolysis. [NurdRage], aka [Dr. N. Butyl Lithium], has developed a process to extract metallic sodium from sodium hydroxide. In fact, everything [NurdRage] used to make the large slugs of sodium is easily and cheaply available – NaOH from drain cleaner, magnesium from fire starters, and mineral oil to keep things calm. The reaction requires an unusual catalyst – menthol – which is easily obtained online. He also gave the reaction a jump-start with a small amount of sodium metal, which can be produced by the lower-yielding but far more spectacular thermochemical dioxane method; lithium harvested from old batteries can be substituted in a pinch. The reaction will require a great deal of care to make sure nothing goes wrong, but in the end, sizable chunks of the soft, gray metal are produced at phenomenal yields of 90% and more. The video below walks you through the whole process.

It looks as though [NurdRage]’s method can be scaled up substantially or done in repeated small batches to create even more sodium. But what do you do when you make too much sodium metal and need to dispose of it? Not a problem.

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Chemistry And Lasers Turn Any Plastic Surface Into A PCB

September 4, 2018 by 30 Comments

On the face of it, PCB production seems to pretty much have been reduced to practice. Hobbyists have been etching their own boards forever, and the custom PCB fabrication market is rich with vendors whose capabilities span the gamut from dead simple one-side through-hole boards to the finest pitch multilayer SMD boards imaginable.

So why on Earth would we need yet another way to make PCBs? Because as [Ben Krasnow] points out, the ability to turn almost any plastic surface into a PCB can be really handy, and is not necessarily something the fab houses handle right now. The video below shows how [Ben] came up with his method, which went down a non-obvious path that was part chemistry experiment, part materials science. The basic idea is to use electroless copper plating, a method of depositing copper onto a substrate without using electrolysis.

This allows non-conductive substrates — [Ben] used small parts printed with a Formlabs SLA printer — to be plated with enough copper to form solderable traces. The chemistry involved in this is not trivial; there are catalysts and surfactants and saturated solutions of copper sulfate to manage. And even once he dialed that in, he had to figure out how to make traces and vias with a laser cutter. It was eventually successful, but it took a lot of work. Check out the video below to see how he got there, and where he plans to go next.

You’ve got to hand it to [Ben]; when he decides to explore something, he goes all in. We appreciate his dedication, whether he’s using candles to explore magnetohydrodynamics or making plasma with a high-speed jet of water.

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The Platinum Catalyst Use In A Vintage Lighter

November 1, 2014 by 14 Comments

[Ben Krasnow] has an inimitable knack for choosing the most interesting concepts for his experiments. We’re sure it’s a combination of base knowledge and epic-curiosity. This time around he’s showing off a vintage cigarette lighter whose quirk is not needing to be “struck” to produce a flame. It’s a catalytic lighter that uses platinum to ignite methanol vapors.

The concept shown in the video below is platinum’s catalyst properties with some types of flammable gasses. The image above shows the cap of the lighter which includes a protective cage around a hunk of fine platinum powder known as platinum black. It is suspended by platinum wire and as the hydrogen passes by the reaction causes the platinum black and wire to glow red-hot.

This simple, quick experiment fills in our own knowledge gaps. We were already familiar with the role that catalytic converters play in automobiles; consuming any unburned hydrocarbons before they exit a vehicle’s exhaust system. We also know the these devices are targets for thieves seeking the platinum (and other metals like palladium and rhodium) found inside. Now we know exactly how catalytic converters work and the integral role that platinum plays in the process. All thanks to [Ben’s] demonstration of how this lighter works.

Now, if you wear a platinum wedding band and your hand passes a jet of hydrogen are you likely to get burned?

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