You won't be able to use two different cards to make a tax payment through Turbotax, but you can use the IRS site to make two or more separate payments. You can use the link below to make payments by credit/debit card.
Inside TurboTax, you should select “pay by check” during the filing process. It will produce a payment voucher for you, which you can then ignore and make the credit/debit card payments online. Or, you can use the voucher to pay some by check if you wish (though you can make a bank draft payment at the link below also).