Speaker 1: Welcome to Tech Stuff, a production from I Heart Radio. Hey,
Speaker 1: they're in Welcome to Tech Stuff. I'm your host, John
Speaker 1: than Strickland. I'm an executive producer with iHeart Radio. And
Speaker 1: how the tech are you? You know? I read an
Speaker 1: interesting article from the Imperial College in London about how
Speaker 1: researchers at that college had developed an alternative catalyst for
Speaker 1: technologies like fuel cells, potentially opening the door to making
Speaker 1: that tech much more affordable, and I thought it might
Speaker 1: be good to do a tech stuff tidbits about fuel cells,
Speaker 1: specifically hydrogen fuel cells, and to talk about that specific
Speaker 1: development with catalysts as well. So first, what the heck
Speaker 1: is a fuel cell? Well, in some ways it's very
Speaker 1: similar to a battery. Batteries and fuel cells both rely
Speaker 1: upon chemical reactions that create an output of electricity. So
Speaker 1: with batteries, you've got yourself a closed system, right. All
Speaker 1: the chemicals are contained within the battery, and what's in
Speaker 1: the battery stays in the battery unless you get a
Speaker 1: battery leak, in which case you really need to take
Speaker 1: care of that because battery acid can be nasty stuff.
Speaker 1: But yeah, the chemical reactions inside the battery will eventually
Speaker 1: slow down and ultimately stop as there will not be
Speaker 1: enough reactive elements remaining in the battery for the reaction
Speaker 1: to continue in the battery goes dead. Rechargeable batteries can
Speaker 1: reverse those reactions, and recharging is really just the opposite
Speaker 1: of discharging, So instead of having electric current flowing out
Speaker 1: of the battery, you make electric current flow into the battery,
Speaker 1: and this reverses those chemical reactions, so you end up
Speaker 1: with the original reactive elements inside the battery. Eventually, even
Speaker 1: rechargeable batteries go dead because you ever really reverse all
Speaker 1: of the chemical reactions, some stuff ends up becoming alert,
Speaker 1: and over time, more and more of those chemicals become inert,
Speaker 1: until your battery just isn't putting up very much juice
Speaker 1: and ultimately will be useless. But what about fuel cells, Well,
Speaker 1: a fuel cell is different from a battery because you
Speaker 1: refuel a fuel cell, you've got your reactive elements that
Speaker 1: are inside the fuel cell and the reactions that they
Speaker 1: go through release electricity. But in the process the fuel
Speaker 1: is spent, it is converted into something else, and once
Speaker 1: that happens, you have to add more fuel to the
Speaker 1: fuel cell and the process can continue. But let's get
Speaker 1: a little more detailed. So, the type of fuel cells
Speaker 1: that we frequently talk about when we discuss stuff like
Speaker 1: fuel cell powered vehicles, for example, are a type called
Speaker 1: polymer electrolyte membrane fuel cells. Now, this is just one
Speaker 1: of many different kinds of fuel cells. Uh, there are
Speaker 1: a lot of different ones that are good for specific
Speaker 1: types of applications. However, we're gonna focus on this because
Speaker 1: it's the type that the average person might encounter should
Speaker 1: fuel cell vehicles become more of a thing in the future.
Speaker 1: And to be clear, they're a thing right now. There
Speaker 1: are fuel cell vehicles out there, some of you might
Speaker 1: even drive one, I don't know, but they're not common.
Speaker 1: So with these fuel cells, you have several components. You've
Speaker 1: got a polymer electrolyte membrane. That's what gives this type
Speaker 1: of fuel cell its name. And let's break down what
Speaker 1: that means. All right, So membrane, I think we pretty
Speaker 1: much all have a handle on that, right, It's a
Speaker 1: thin boundary between two things. And an electrolyte is a
Speaker 1: material that contains ions. Ions are charged atoms, So you're
Speaker 1: talking about atoms that either have more protons than they
Speaker 1: have electrons, so they would be positively charged. Because protons
Speaker 1: carry a positive charge, electrons carry and negative. If you
Speaker 1: have the same number, then the opposite charges neutralize each other.
Speaker 1: It's a neutrally charged atom. So an ion has to
Speaker 1: have either more protons than electrons, or more electrons than
Speaker 1: it has protons. In that case, you would have a
Speaker 1: negatively charged ion. UM. A polymer is a long chain molecule.
Speaker 1: Plastics are a type of polymer um, and there are
Speaker 1: lots of naturally occurring polymers, including some naturally occurring plastics,
Speaker 1: though we don't really think of natural plastics when we
Speaker 1: use the word plastic. Now. I mentioned that the membrane
Speaker 1: acts as a boundary, Well what is it a boundary for?
Speaker 1: It acts as a barrier between the two sides of
Speaker 1: the fuel cell. You can think of it as like
Speaker 1: a gateway, if you will. So, on one side, which
Speaker 1: is the cathode side of the fuel cell, you have oxygen.
Speaker 1: On the other side, the anode side of the fuel cell,
Speaker 1: you have of hydrogen. Hydrogen happens to be the most
Speaker 1: plentiful element in our universe. However, it's also highly reactive.
Speaker 1: It bonds with other elements readily, so readily. In fact,
Speaker 1: that pretty much we only find hydrogen informs where it
Speaker 1: has bonded with something else. So when hydrogen bonds with oxygen,
Speaker 1: we get water H two O, you know, two hydrogen
Speaker 1: atoms and an oxygen atom, and then things get all
Speaker 1: splichy splashy. So in a fuel cell, the hydrogen quote
Speaker 1: unquote wants to bond with the oxygen and form water.
Speaker 1: But you've got this pesky membrane that acts kind of
Speaker 1: like a bouncer in a club, and this bouncer doesn't
Speaker 1: want any neutral glum hydrogen atoms coming in. You know,
Speaker 1: a hydrogen atom. A standard hydrogen atom consists of a
Speaker 1: single proton and a single electron. Well, that's positive neck
Speaker 1: of charge cancels each other out. You've gotta neutrally charged atom.
Speaker 1: The membranes like, sorry, we only want positive folks in here,
Speaker 1: so you can't come in. And the bouncer definitely doesn't
Speaker 1: want any negative nancies coming in, so no negativity. So
Speaker 1: the only way it will let a hydrogen atom pass
Speaker 1: through the membrane is if the hydrogen atom chucks it's
Speaker 1: one electron and becomes a hydrogen ion, also known as
Speaker 1: a proton. Because again, the hydrogen atom is it consists
Speaker 1: of a single proton and a single electron. So if
Speaker 1: a hydrogen atom gets rid of its electron, it is
Speaker 1: a hydrogen ion. It's also a proton. Now, once it
Speaker 1: is free of its electron, the hydrogen atom can just
Speaker 1: waltz right on by the bouncer and pass over to
Speaker 1: the oxygen side. We we will just call that club
Speaker 1: oxygen on the other side of the membrane. But here's
Speaker 1: the thing. Chucking an electron isn't so simple, right, Like,
Speaker 1: typically we would have to pour energy into the system
Speaker 1: to start stripping electrons away, because we would excite an
Speaker 1: electron so that it would move further out from the
Speaker 1: nucleus of the atom until you could make it go
Speaker 1: do something. So, the hydrogen atom cannot just shed an
Speaker 1: electron all by itself. It needs a catalyst. Now, if
Speaker 1: you remember from your chemistry, a catalyst is something that
Speaker 1: facilitates a chemical reaction. The catalyst itself isn't getting like,
Speaker 1: it's not part of the reaction in the sense of
Speaker 1: it is undergoing a change. It can increase the rate
Speaker 1: of a chemical reaction without itself undergoing any significant or
Speaker 1: permanent change, and We'll touch on the catalyst issue in
Speaker 1: a moment, because that's the key of the research I
Speaker 1: was talking about the beginning of the episode. So the hydrogen,
Speaker 1: with the help of this catalyst, sheds an electron and
Speaker 1: becomes a proton, a positively charged particle, and then it
Speaker 1: can pass through the membrane. Now, electrons have a negative charge,
Speaker 1: and negatively charged particles repel other negatively charged particles. We
Speaker 1: know this right, Like charge repels like opposite charges attract,
Speaker 1: So that means the electrons are attracted to the positively
Speaker 1: charged particles that are on the other side of the membrane.
Speaker 1: So the electrons quote unquote want to get through the
Speaker 1: membrane and rejoin the positively charged hydrogen at ions aka
Speaker 1: the protons on the other side. But that pesky bouncer
Speaker 1: won't let the electrons through. It will not let that happen.
Speaker 1: So the electrons are not on the guest list. They
Speaker 1: aren't allowed inside. But if you were to provide a
Speaker 1: pathway like a circuit for the electrons to pass through
Speaker 1: so that they could ultimately rejoin the positively charged ions
Speaker 1: that are on the other side, like, they may have
Speaker 1: to go a much further distance and they might have
Speaker 1: to do some work. Well, they're still gonna jump at
Speaker 1: the chance. So this is how you make electrons go
Speaker 1: and power something. You have electricity right the flow of electrons,
Speaker 1: and then ultimately they can make their way over to
Speaker 1: club oxygen. They're just going through like a side door
Speaker 1: as opposed to the front door. And this is how
Speaker 1: fuel cells supply electricity, although we you know, don't actually
Speaker 1: use the analogy of a bouncer in a club. So
Speaker 1: the electrons that have been shed by hydrogen will flow
Speaker 1: into a circuit and ultimately join up with the oxygen
Speaker 1: atoms and the hydrogen ions all over in club oxygen.
Speaker 1: Once the electrons get there, well then they can zip
Speaker 1: on over to those hydrogen ions, and you have hydrogen
Speaker 1: atoms mixing with oxygen atoms, so you get water molecules.
Speaker 1: This means that in one of these fuel cells, your
Speaker 1: fuel consists of hydrogen and oxygen, your output is electricity,
Speaker 1: and your waste is water vapor. And that's one of
Speaker 1: the big reasons fuel cells come up in discussions of
Speaker 1: green energy because they do not produce carbon dioxide or
Speaker 1: carbon monoxide emissions, at least not if you're using pure
Speaker 1: hydrogen as fuel. More on that in a bit, so
Speaker 1: they just produce electricity and water. Like a car that's
Speaker 1: powered by a fuel cell that's using pure oxygen and
Speaker 1: pure hydrogen wouldn't give off any emissions other than water vapor.
Speaker 1: All right, When we come back, I'll get into a
Speaker 1: little more detail about some of the challenges of fuel
Speaker 1: cells and explain why they aren't everywhere right now. But
Speaker 1: first let's take a quick break. Okay, so fuel cells work.
Speaker 1: There are fuel cell vehicles out there today, though there
Speaker 1: are not a lot of them. So why aren't fuel
Speaker 1: cells more popular? If all you need is the most
Speaker 1: common element that's in the universe on one side, and
Speaker 1: oxygen in the other, and if you can just essentially
Speaker 1: scoop up oxygen from our atmosphere, why aren't we all
Speaker 1: using fuel cell vehicles. There are a few big reasons,
Speaker 1: and one is that fuel cells have an ideal operating temperature.
Speaker 1: Your average polymer electro light membrane fuel cell best operates
Speaker 1: it around eighty degrees celsius or a hundred seventy six
Speaker 1: degrees fahrenheit, which is pretty toasty, and it means that
Speaker 1: in really cold regions it could take a while to
Speaker 1: warm up the fuel cell to a temperature that's high
Speaker 1: enough to generate enough electricity to do whatever it is
Speaker 1: you want to do. You might be familiar like batteries
Speaker 1: don't operate as quickly in very cold temperatures, meaning you
Speaker 1: get less electricity out of a battery. You get, uh,
Speaker 1: electricity that may not be enough for you to do
Speaker 1: whatever it is you need to do. If you've ever
Speaker 1: picked up a flashlight that was sitting in a freezing
Speaker 1: room and turn it on, you I be like wow
Speaker 1: that the light is really weak from this, and then
Speaker 1: over time, as the flash light warms up, the light
Speaker 1: gets stronger. The same sort of thing can happen with
Speaker 1: fuel cells. Like you, you could have a slower chemical
Speaker 1: reaction at lower temperatures, and if it's slow enough, it
Speaker 1: might not be enough to do what you need it
Speaker 1: to do, like power and electric motor for example. Now,
Speaker 1: for another reason why fuel cells aren't everywhere, Uh, they
Speaker 1: deteriorate over time, so you do have to replace them occasionally.
Speaker 1: And then we get to what's a really big drawback.
Speaker 1: They are expensive, and they are expensive because of the catalyst.
Speaker 1: See the typical catalyst used in these types of fuel
Speaker 1: cells is made of platinum. That's a very rare, very
Speaker 1: expensive metal. And even though you only need a relatively
Speaker 1: small amount of platinum per fuel cell, that requirement really
Speaker 1: drives up the price significantly. In fact, according to the
Speaker 1: researchers that Imperial College London, about six of a fuel
Speaker 1: cells cost comes from the platinum that's used for the catalyst.
Speaker 1: That's why the work done by those researchers could be transformative.
Speaker 1: The researchers were able to create a catalyst using iron
Speaker 1: instead of platinum. Now, iron isn't scarce at all. The
Speaker 1: Earth is lousy with the stuff. Iron is plentiful, and
Speaker 1: if we could use iron as a catalyst material instead
Speaker 1: of platinum, that would bring the price of fuel cells
Speaker 1: way down. And let's talk a little bit about what
Speaker 1: those researchers did. They took iron atoms and they embedded
Speaker 1: singular iron atoms within a matrix of carbon, so they had,
Speaker 1: you know, multiple iron atoms in the matrix total, but
Speaker 1: they would in each atom was kind of its own
Speaker 1: little individual part in that section of the matrix. This
Speaker 1: is where we can talk about something that's really interesting
Speaker 1: and it's also a little counterintuitive because we're familiar with
Speaker 1: the way how iron works on moss. Meaning if you've
Speaker 1: got a whole bunch of iron atoms together forming say
Speaker 1: a chunk of iron, we know how iron will behave, right.
Speaker 1: It's on this classic system. However, when you get down
Speaker 1: to an individual iron atom, you're now diving down to
Speaker 1: the nanoscale. Actually you're diving down to the atomic scale,
Speaker 1: which is even smaller than the nano scale. Once you
Speaker 1: start hitting the nanoscale, stuff starts to behave in an
Speaker 1: entirely different way than the way we are used to
Speaker 1: it on the macro scale, and it can in fact
Speaker 1: be really bizarre um on the nano scale, even though
Speaker 1: you're talking about unimaginable tiny particles, those particles have way
Speaker 1: more surface area per unit of mass than what you
Speaker 1: would find at the macro level, and that means that
Speaker 1: more of the material can come into contact with other
Speaker 1: stuff by unit of mass, and the materials behaviors can change.
Speaker 1: One of those behaviors is that material reels can become
Speaker 1: better catalysts at the nano scale or the atomic scale.
Speaker 1: The researchers said that they're iron catalyst, and a carbon
Speaker 1: matrix was able to perform as a good substitute for platinum,
Speaker 1: and that it has performance that is quote unquote approaching platinum.
Speaker 1: So it sounds as if the iron catalysts perhaps isn't
Speaker 1: quite as effective as platinum, but the tradeoff in price
Speaker 1: could more than make up for the decline in performance.
Speaker 1: But performance is just one part of the issue. Another
Speaker 1: one is durability. That's something that the researchers are working
Speaker 1: on now, trying to make the iron solution as durable
Speaker 1: as platinum catalysts. Otherwise you would have to replace the
Speaker 1: catalyst more frequently, which would eat into the cost savings
Speaker 1: of iron. Right if you have to replace it more
Speaker 1: frequently than you would with a platinum catalyst, then the
Speaker 1: benefits start to that that get that that span of
Speaker 1: benefits begins to narrow, I guess, is what I'm trying
Speaker 1: to say. Plus, it becomes a hassle if you have
Speaker 1: to frequently get your fuel cells serviced or replaced. Now,
Speaker 1: if the team can make the iron catalysts stability match
Speaker 1: that of platinum, the breakthrough could lead to a revolution
Speaker 1: and fuel cell technology. However, there is still one more
Speaker 1: thing we have to talk about, and that's hydrogen itself. So,
Speaker 1: as I mentioned, it's the most plentiful stuff in the universe,
Speaker 1: but it also tends to bond with other elements really easily,
Speaker 1: and that's the tricky bit. To get at hydrogen, we
Speaker 1: typically have to exert energy to do it. We can't
Speaker 1: just go and collect hydrogen pure hydrogen on its own.
Speaker 1: It's almost always bonded to something else, So we have
Speaker 1: to find a way to break those chemical bonds that
Speaker 1: hold hydrogen to whatever it happens to be bonded with. Well,
Speaker 1: when you start to look at fuel cells from an
Speaker 1: energy ecosystem point of view, you have to start asking
Speaker 1: tough questions like do you have to spend more energy
Speaker 1: to get the hydrogen then you are getting out of
Speaker 1: using it in a fuel cell? And how are you
Speaker 1: getting at the hydrogen? Is it as efficient as it
Speaker 1: can be? Is it environmentally friendly because some of the
Speaker 1: ways we get hydrogen is definitely not environmentally friendly. In fact,
Speaker 1: the primary way we get hydrogen is we collected as
Speaker 1: a byproduct from natural gas processing and and natural gas
Speaker 1: is a fossil fuel. So if we assume that that's
Speaker 1: how we're gonna keep getting hydrogen, it means we're presuming
Speaker 1: that we're going to continue to depend on fossil fuels,
Speaker 1: and that is an issue, right. It means that we're
Speaker 1: still doing something that itself is environmentally harmful. We can
Speaker 1: use hydrogen without breaking those bonds in some forms of
Speaker 1: hydrocarbon gases, but that would mean that we would actually
Speaker 1: have emissions beyond just water vapor. It might include carbon
Speaker 1: monoxide for example. So you know, you could have fuel
Speaker 1: cells that use hydrogen that's in a mixture of something else,
Speaker 1: like a hydrocarbon gas, but you have down downsides to
Speaker 1: that as well. There are other ways we can get
Speaker 1: hydrogen that don't involve fossil fuels. One way is just
Speaker 1: to do what fuel cells do, but in reverse. So
Speaker 1: remember with fuel cells, we take hydrogen and oxygen and
Speaker 1: using that membrane and a catalyst, we get electricity and
Speaker 1: water vapor as byproducts of the chemical reaction. But then
Speaker 1: if you were to take water and pass an electrical
Speaker 1: current through the water, you would break the molecular bonds
Speaker 1: between hydrogen and oxygen and you would get O two
Speaker 1: and H two gases. But again that means you have
Speaker 1: to expend energy in order to release the hydrogen and oxygen.
Speaker 1: If you're expending the same amount of energy as you
Speaker 1: would be getting out of the fuel cells. You're not
Speaker 1: really seeing a benefit here, really, you're just shifting where
Speaker 1: the load is. One way to approach this is by
Speaker 1: using renewable energy sources to create the electrical current you
Speaker 1: need to break those molecular bonds in a process is
Speaker 1: called electrolysis. Anyway, harvesting hydrogen presents its own big challenges. Yes,
Speaker 1: the use of hydrogen and fuel cells is clean energy,
Speaker 1: but getting at the hydrogen might not be so clean.
Speaker 1: There's always a catch still. With the possibility of fuel
Speaker 1: cells becoming more economically feasible, that could encourage more r
Speaker 1: and d into how we can collect hydrogen in a
Speaker 1: more environmentally conscious way. And who knows, maybe we'll get
Speaker 1: that hydrogen economy that folks were talking about nearly twenty
Speaker 1: years ago. And that's it. Protect Stuff Tidbits. Hope you
Speaker 1: enjoyed this. I'll talk to you again really soon. Text
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