I would preface by saying it's probably best to contact a tax professional.
Beyond that this thread is semi relevant, albeit about illiquid penny stocks as opposed to crypto: How do I get rid of worthless penny stocks if there is no volume (so market/limit orders don't work) and my broker won't buy them from me?
Given the basis for crypto as investment tax treatment the following is relevant.
Rather topical is 26 CFR § 1.165-2 Obsolescence of nondepreciable property, which are IRS regulations concerning income tax and deductions, namely parapgraph (a):
§ 1.165-2 Obsolescence of nondepreciable property. (a) Allowance of
deduction. A loss incurred in a business or in a transaction entered
into for profit and arising from the sudden termination of the
usefulness in such business or transaction of any nondepreciable
property, in a case where such business or transaction is discontinued
or where such property is permanently discarded from use therein,
shall be allowed as a deduction under section 165(a) for the taxable
year in which the loss is actually sustained. For this purpose, the
taxable year in which the loss is sustained is not necessarily the
taxable year in which the overt act of abandonment, or the loss of
title to the property, occurs.
To my understanding as long as the coins were purchased with the intention of making a profit, they suddenly stopped having value, it is nondepreciable property (which crypto is), and they are permanently discarded (such as sent to a null address) they could be considered abandoned property loss and thus written off. However, and very importantly to do so you would need to ensure everything is properly documented. Specifically, proof of ownership pre abandonment, intent to abandon, and what you did to abandon said property.
Relevant tax court test: https://www.thetaxadviser.com/issues/2018/nov/loss-deductions-abandonment-intangible-assets.html
The losses would then be reported on the form 4797 line 10 as an ordinary loss.
See the following: https://www.cointracker.io/blog/write-off-cryptocurrencies-with-no-value
I am neither a lawyer nor tax professional, and would once again recommending speaking to either or both prior to taking any action.