K (ngn/k), 22 bytes
Returns odd output before even output.
2/64 2#,/|@\^:\(64#2)\
(64#2)\
Get an array of all bits of the integer.,/|@\^:\
Magic incantation to repeat the leading bit 65 times. Works something like: make all bits zero, index into the array of bits, prepend that result to the bits.64 2#
Reshape the length 128 array into a matrix with two columns.2/
Convert both columns from base 2.