No, you won't be able to split the payment between two credit cards using TurboTax. Instead choose "Pay by check" and then e-file. After you e-file, you can use the IRS website below to make two separate payments with a credit card directly to the IRS.
Yes, but only on the IRS web site. Turbotax can't split the payment. See the expert's answer for how to make two payments directly on the IRS web site.