Using tensorflow command in keras - python-2.7

Question

Is it possible in keras to use tensorflow tensor manipulations commands for altering the shape of data, of split by an axis or somethign like that..
I am currently trying something like this:
def row_convolution(input):
filter_size = 8
temp_list = []
input = tf.placeholder(tf.float32,shape=(None,33,1,8,45,3))
for section in tf.unstack(input,axis=1):
section = tf.reshape(section,[1,8,45,3])
temp_list.append((Conv2D(filters = 1, kernel_size = (8,45), activation='relu' , name = 'conv')(section)))
print "len: " + str(len(temp_list))
return tf.convert_to_tensor(np.array(temp_list))
Which is is the function for a lamdba layer, but the last command give me an error message stating:
Traceback (most recent call last):
File "keras_cnn_phoneme_original_fit_generator.py", line 182, in <module>
fws()
File "keras_cnn_phoneme_original_fit_generator.py", line 167, in fws
model.add(Lambda(row_convolution,input_shape = (33,1,8,45,3)))
File "/usr/local/lib/python2.7/dist-packages/keras/models.py", line 422, in add
layer(x)
File "/usr/local/lib/python2.7/dist-packages/keras/engine/topology.py", line 554, in __call__
output = self.call(inputs, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/keras/layers/core.py", line 659, in call
return self.function(inputs, **arguments)
File "keras_cnn_phoneme_original_fit_generator.py", line 147, in row_convolution
return tf.convert_to_tensor(np.array(temp_list))
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/framework/ops.py", line 637, in convert_to_tensor
as_ref=False)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/framework/ops.py", line 702, in internal_convert_to_tensor
ret = conversion_func(value, dtype=dtype, name=name, as_ref=as_ref)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/framework/constant_op.py", line 110, in _constant_tensor_conversion_function
return constant(v, dtype=dtype, name=name)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/framework/constant_op.py", line 99, in constant
tensor_util.make_tensor_proto(value, dtype=dtype, shape=shape, verify_shape=verify_shape))
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/framework/tensor_util.py", line 451, in make_tensor_proto
append_fn(tensor_proto, proto_values)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/framework/tensor_util.py", line 109, in SlowAppendObjectArrayToTensorProto
tensor_proto.string_val.extend([compat.as_bytes(x) for x in proto_values])
File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/util/compat.py", line 65, in as_bytes
(bytes_or_text,))
TypeError: Expected binary or unicode string, got <tf.Tensor 'lambda_1/conv/Relu:0' shape=(1, 1, 1, 1) dtype=float32>