An absurd consequence of the second law of thermodynamics is that catalysts accelerate the forward and backward reactions "equally", "by the same factor":
"Suppose that, as indicated in the figure, the catalyst affects only the forward reaction. In its presence, the sum of the forward rates would clearly be larger than otherwise, while the backward rate would be unchanged. The position of equilibrium would therefore shift to the right, by the law of mass action. If we suppose further that the reaction produces heat q when it occurs, then a violation of the second law would be possible. We first allow equilibrium to be reached without the catalyst...and then add the catalyst, and heat δq is produced as the equilibrium is shifted. This heat is used to run a machine, and thus do work, cooling the system back to its original temperature in the process. We then remove the catalyst and the equilibrium shifts back. Heat δq is now extracted from the surroundings, which must warm the system back to the ambient temperature. A cycle has therefore been completed for which the net effect has been the isothermal conversion of heat energy into work, and a perpetual motion machine of the second kind has been found. We conclude that the supposed situation is impossible and that the catalyst must accelerate the forward and backward reactions equally." https://dtk.tankonyvtar.hu/bitstream/handle/123456789/8903/B9780120442621500128.pdf
"It is important to recognize that when an enzyme (or any catalyst) lowers the activation energy for the reaction A → B, it also lowers the activation energy for the reaction B → A by exactly the same amount (see Figure 2-44). The forward and backward reactions will therefore be accelerated by the same factor by an enzyme..." https://www.ncbi.nlm.nih.gov/books/NBK26838/
Scientists should have exposed the absurdity of this particular consequence of the second law long ago, and should have applied reductio ad absurdum: Since the consequence is absurd, the underlying premise, the second law of thermodynamics, is false.
Consider the dissociation-association reaction
A ⇌ B + C
which is in equilibrium. We add a catalyst and it starts splitting A - the rate constant of the forward (dissociation) reaction increases by a factor of, say, 745492. If the second law of thermodynamics is obeyed, the catalyst must increase the rate constant of the reverse (association) reaction by exactly the same factor, 745492. But this is insane! The reverse reaction is entirely different from the forward one: B and C must first get together, via diffusion, and only then can the catalyst join them to form A. Catalysts don't speed up diffusion!
There are countless examples of biased and even unidirectional catalysis in the literature but in most cases the available information does not allow one to unequivocally conclude that the second law is violated. There are exceptions of course:
"In 2000, a simple, foundational thermodynamic paradox was proposed: a sealed blackbody cavity contains a diatomic gas and a radiometer whose apposing vane surfaces dissociate and recombine the gas to different degrees (A_2 ⇌ 2A). As a result of differing desorption rates for A and A_2 , there arise between the vane faces permanent pressure and temperature differences, either of which can be harnessed to perform work, in apparent conflict with the second law of thermodynamics. Here we report on the first experimental realization of this paradox, involving the dissociation of low-pressure hydrogen gas on high-temperature refractory metals (tungsten and rhenium) under blackbody cavity conditions. The results, corroborated by other laboratory studies and supported by theory, confirm the paradoxical temperature difference and point to physics beyond the traditional understanding of the second law." https://link.springer.com/article/10.1007/s10701-014-9781-5
"A simple device is introduced that utilizes the phenomenon of epicatalysis to establish a stationary temperature difference by which ambient environmental thermal energy might be converted into useful work...Traditional catalysis is a central pivot around which much of the industrial and biological worlds turn. Positive catalysts satisfy three general principles. First, they increase reaction rates by providing lower activation energies for rate-limiting steps. Second, they are not consumed by their net reactions although they are intimately involved in them. Third, they do not alter final thermodynamic equilibria of their reactions. Epicatalysts bend this third principle in that they shift the final gas-phase equilibria of reactions." D. P. Sheehan, T. M. Welsh, Epicatalytic thermal diode: Harvesting ambient thermal energy, Sustainable Energy Technologies and Assessments, Volume 31, February 2019, Pages 355-368 https://www.sciencedirect.com/science/article/pii/S2213138818301838
"A research team from three U.S. Department of Energy (DOE) national laboratories and four universities found that subtle changes to the environment surrounding some enzymes can not only change the rate of a cellular reaction by a staggering six orders of magnitude but also its direction. That reversal—the root of the catalytic bias dilemma—is like speeding in one direction at 10 miles-per-second, then going in the opposite direction at 1,000,000 miles-per-second." https://www.pnnl.gov/news-media/remarkable-rate-return-catalytic-bias
Far from accelerating the forward and backward reactions "equally", in this experiment
Yu Hang Li et al. Unidirectional suppression of hydrogen oxidation on oxidized platinum clusters https://www.nature.com/articles/ncomms3500
a catalyst accelerates only the forward reaction, 2H+ → H_2, and SUPPRESSES the backward reaction, H_2 → 2H+. Violation of the second law par excellence.
Pentcho Valev https://twitter.com/pentcho_valev
