The phrase "appeared difficult to" is correct and usable in written English.
It can be used when describing a situation or task that seems challenging or hard to accomplish.
Example: "The project appeared difficult to manage due to the tight deadlines and limited resources."
Alternatives: "seemed hard to" or "looked challenging to".
She said the racial claims appeared "difficult to discern".
Although first-round winners in most of the groups appeared difficult to predict, Argentina was clearly the dominant power in a group that also includes England and Sweden.
Using contemporary scenario techniques it appeared difficult to find a future tourist travel system consistent with CO2 emission reductions of up to 70% by 2050 with respect to 2005.
The main issues appeared difficult to overcome: his sluggish pace; his reckless tackling; his discipline was under the microscope with two red cards and verbal caution from Arsène Wenger about lunging in.
On all sides and from all directions, it appeared difficult to bring a faithful intellectual contribution to bear in a coordinated way on performing the perennial tasks of Christian doctrine.
According to the minutes, "a few members" pointed out that the goal of 2 percent inflation appeared "difficult to achieve" in the planned time frame of about two years, "since it was highly uncertain whether changes in inflation expectations would lead to a rise in the actual rate of inflation".
Alas, it appears difficult to have both.
This result appears difficult to explain in terms of existing theories of recollection and familiarity.
On arrival, it initially appears difficult to buy anything other than thongs, hosiery and bustiers.
Blocking back however appears difficult to deal with (while retaining the convergence guarantee) and represents an area for further study.
It appears difficult to control since it has an opportunistic diet and the capacity for explosive population growth.
